LTC1536

Precision Triple Supply Monitor

for PCI Applications

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

PUSHBUTTON

RESET

PCI
LOCAL
BUS

SELECTED TO MEET RISE TIME

SLEW RATE REQUIREMENTS (1k MIN)

3.3V

0.3V

0.1

RST

1536 TA01

PWR GOOD

0.1

Motherboard PCI RST Generation

TIME (20ns/DIV)

VOLTAGE (1V/DIV)

1536 TA02

CC5

= 5V TO 3V STEP

CC3

= V

CCA

= 3.3V

4.7k PULL-UP FROM
RST TO V

CC3

RST

CC5

Power Fail Waveform

5V Dropping Below 3.3V by 300mV

Simultaneously Monitors 5V, 3.3V and
Adjustable Inputs

Guaranteed Threshold Accuracy:

0.75%

Low Supply Current: 100

Internal Reset Time Delay: 200ms

Manual Pushbutton Reset Input

Active Low and Active High Reset Outputs

Active Low "Soft" Reset Output

Power Supply Glitch Immunity

Guaranteed Reset for Either V

CC3

1V or V

CC5

Meets PCI t

FAIL

Timing Specifications Rev 2.1

8-Pin SO and MSOP Packages

The LTC

1536 is designed for PCI local bus applications

with multiple supply voltages that require low power,
small size, high speed and high accuracy supply
monitoring.

For 3.3V and 5V supplies that are > 500mV below spec or
for the condition when the 5V supply falls below the 3.3V
supply, the LTC1536 has a very fast response time capable
of meeting the PCI t

FAIL

timing specification. Tight 0.75%

threshold accuracy and glitch immunity ensure reliable
reset operation without false triggering.

The RST output is guaranteed to be in the correct state for
V

CC5

or V

CC3

down to 1V. The 100

A typical supply current

makes the LTC1536 ideal for power-conscious systems.

A manual pushbutton reset input provides the ability to
generate a very narrow "soft" reset pulse (100

s typ) or a

200ms reset pulse equivalent to a power-on reset. Both
SRST and RST outputs are open-drain and can be OR-tied
with other reset sources.

PCI-Based Systems

Desktop Computers

Notebook Computers

Intelligent Instruments

Portable Battery-Powered Equipment

Network Servers

, LTC and LT are registered trademarks of Linear Technology Corporation.

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO

LTC1536

BSOLUTE

(Notes 1, 2)

Terminal Voltage

CC3

, V

CC5

, V

CCA

.................................... 0.3V to 7V

RST, SRST ............................................ 0.3V to 7V
RST ......................................... 0.3V to V

CC3

+ 0.3V

PBR .......................................................... 7V to 7V

Operating Temperature Range

LTC1536C .............................................. 0

C to 70

LTC1536I ............................................ 40

C to 85

Storage Temperature Range ................ 65

C to 150

Lead Temperature (Soldering, 10 sec)................. 300

PACKAGE/ORDER I FOR ATIO

ORDER

PART NUMBER

ORDER

PART NUMBER

LTC1536CMS8

TOP VIEW

S8 PACKAGE

8-LEAD PLASTIC SO

CC3

CC5

CCA

GND

PBR

SRST

RST

JMAX

= 125

= 150

C/ W

1
2
3
4

CC3

CC5

CCA

GND

8
7
6
5

PBR
SRST
RST
RST

TOP VIEW

MS8 PACKAGE

8-LEAD PLASTIC MSOP

JMAX

= 125

= 160

C/ W

MS8 PART MARKING

LTBV

Consult factory for Military grade parts.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

RT3

Reset Threshold V

CC3

2.962

2.985

3.000

2.925

2.985

3.008

RT5

Reset Threshold V

CC5

4.687

4.725

4.750

4.625

4.725

4.762

RTA

Reset Threshold V

CCA

0.992

1.000

1.007

0.980

1.000

1.007

CC3

or V

CC5

Operating Voltage

RST in Correct Logic State

VCC3

CC3

Supply Current

PBR = V

CC3

100

200

VCC5

CC5

Input Current

CC5

= 5V

VCCA

CCA

Input Current

CCA

= 1V, 0

CCA

= 1V, 40

RST

Reset Pulse Width

RST Low with 10k

Pull-Up to V

CC3

C to 70

140

200

280

C to 85

140

200

300

SRST

Soft Reset Pulse Width

SRST Low with 10k

Pull-Up to V

CC3

100

200

Undervoltage Detect to RST

CC5

, V

CC3

or V

CCA

Less Than Reset

Threshold V

by 1%

ELECTRICAL CHARACTERISTICS

CC3

= 3.3V, V

CC5

= 5V, V

CCA

= V

CC3

, T

= 25

C unless otherwise noted.

S8 PART MARKING

1536
1536I

LTC1536CS8
LTC1536IS8

LTC1536

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

PBR

PBR Pull-Up Current

PBR = 0V, 0

PBR = 0V, 40

PBR, RST Input Low Voltage

0.8

PBR, RST Input High Voltage

PBR Min Pulse Width

PBR Debounce

Deassertion of PBR Input to SRST

Output (PBR Pulse Width = 1

PBR Assertion Time for Transition

PBR Held Less Than V

, 0

C to 70

1.4

2.0

2.8

from Soft to Hard Reset Mode

PBR Held Less Than V

, 40

C to 85

1.4

2.0

3.0

RST Output Voltage Low

SINK

= 5mA

0.15

0.4

SINK

= 100

CC3

= 1V, V

CC5

= 0V

0.05

0.4

CC3

= 0V, V

CC5

= 1V

0.05

0.4

CC3

= 1V, V

CC5

= 1V

0.05

0.4

SINK

= 100

CC3

= 1.1V, V

CC5

= 0V

0.05

0.4

CC3

= 0V, V

CC5

= 1.1V

0.05

0.4

CC3

= 1.1V, V

CC5

= 1.1V

0.05

0.4

SRST Output Voltage Low

SINK

= 2.5mA

0.15

0.4

RST Output Voltage Low

SINK

= 2.5mA

0.15

0.4

RST Output Voltage High (Note 3)

SOURCE

= 1

CC3

SRST Output Voltage High (Note 3)

SOURCE

= 1

CC3

RST Output Voltage High

SOURCE

= 600

CC3

PHL

Propagation Delay RST to RST

RST

= 20pF

High Input to Low Output

PLH

Propagation Delay RST to RST

RST

= 20pF

Low Input to High Output

FAIL

CC5

or V

CC3

0.5V Undervoltage

CC5

Drops Below 4.25V or V

CC3

Drops

150

450

to RST (Note 4)

Below 2.5V (Note 5)

CC5

< (V

CC3

300mV) RST (Note 4)

CC5

Drops Below V

CC3

By 300mV

(Note 6)

ELECTRICAL CHARACTERISTICS

CC3

= 3.3V, V

CC5

= 5V, V

CCA

= V

CC3

, T

= 25

C unless otherwise noted.

Note 4: Conforms to PCI Local Bus Specification Rev 2.1,
Sect. 4.3.2 for t

FAIL

Note 5: V

CC3

or V

CC5

falling at 0.1V/

s, time measured from

RTX

500mV to RST at 1.5V.

Note 6: V

CC5

falling from 5V to 3V in

10ns, time measured from

CC5

= (V

CC3

300mV) to RST at 1.5V.

The

denotes specifications which apply over the full operating

temperature range.

Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.

Note 2: All voltage values are with respect to GND.

Note 3: The output pins SRST and RST have weak internal pull-ups to
V

CC3

of 6

A. However, external pull-up resistors may be used when faster

rise times are required.

LTC1536

TYPICAL PERFOR

CE CHARACTERISTICS

CCA

Input Current

vs Input Voltage

TEMPERATURE (

VCC3

(

140

120

1536 G01

100

VCC3

vs Temperature

INPUT VOLTAGE (V)

0.8

INPUT CURRENT (nA)

0.9

1.0

1.1

1.2

1536 G03

0.85

0.95

1.05

1.15

= 25

TEMPERATURE (

VCC5

(

2.5

5.0

7.5

10.0

20.0

15.0

1536 G02

17.5

12.5

VCC5

vs Temperature

TEMPERATURE (

CC5

THRESHOLD VOLTAGE, V

RT5

(V)

4.750

4.745

4.740

4.735

4.730

4.725

4.720

4.715

4.710

4.705

4.700

1536 G04

100

CC5

Threshold Voltage

vs Temperature

CCA

Threshold Voltage

vs Temperature

TEMPERATURE (

CCA

THRESHOLD VOLTAGE, V

RTA

(V)

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

1536 G06

100

CC3

Threshold Voltage

vs Temperature

TEMPERATURE (

CC3

THRESHOLD VOLTAGE, V

RT3

(V)

1536 G05

100

3.010

3.005

3.000

2.995

2.990

2.985

2.980

2.975

2.970

2.965

2.960

PBR Assertion Time to Reset
vs Temperature

Reset Pulse Width
vs Temperature

TEMPERATURE (

210

215

220

1536 G07

205

200

100

195

190

RESET PULSE WIDTH, t

RST

(ms)

225

"Soft" Reset Pulse Width
vs Temperature

TEMPERATURE (

105.0

107.5

110.0

1536 G08

102.5

100.0

100

97.5

95.0

SOFT RESET PULSE WIDTH, t

SRST

(

112.5

TEMPERATURE (

2.10

2.15

2.20

1536 G09

2.05

2.00

100

1.95

1.90

PBR ASSERTION TIME TO RESET, t

(SEC)

2.25

LTC1536

TYPICAL PERFOR

CE CHARACTERISTICS

CC3

Typical Transient Duration

vs Reset Comparator Overdrive

CCA

Typical Transient Duration

vs Reset Comparator Overdrive

CC3

RESET COMPARATOR OVERDRIVE, V

RT3

CC3

(V)

0.001

TYPICAL TRANSIENT DURATION (

0.01

0.1

1536 G10

RESET OCCURS
ABOVE CURVE

CCA

RESET COMPARATOR OVERDRIVE, V

RTA

CCA

(V)

0.001

TYPICAL TRANSIENT DURATION (

0.01

0.1

1536 G12

RESET OCCURS
ABOVE CURVE

CC5

Typical Transient Duration

vs Reset Comparator Overdrive

CC5

RESET COMPARATOR OVERDRIVE, V

RT5

CC5

(V)

0.001

TYPICAL TRANSIENT DURATION (

0.01

0.1

1536 G11

RESET OCCURS
ABOVE CURVE

RST Output Voltage
vs Supply Voltage

SUPPLY VOLTAGE, V

(V)

RST OUTPUT VOLTAGE (V)

3.0

4.0

5.0

4.0

1536 G13

2.0

1.0

2.5

3.5

4.5

1.5

0.5

1.0

2.0

3.0

0.5

4.5

1.5

2.5

3.5

5.0

CC5

= V

CC3

= V

CCA

4.7k PULL-UP FROM RST TO V

CC5

= 25

Undervoltage Response Time
vs Temperature

TIME (1

s/DIV)

VOLTAGE (500mV/DIV)

1536 G15

CC3

RST

MARGIN

DEVICE THRESHOLD

PCI SPEC

FAIL

SPEC

CC3

FALLING

FROM 3.3V TO
2.3V AT ( 0.1V/

RST Output Voltage
vs Supply Voltage

SUPPLY VOLTAGE, V

(V)

RST OUTPUT VOLTAGE (V)

3.0

4.0

5.0

4.0

1536 G16

2.0

1.0

2.5

3.5

4.5

1.5

0.5

1.0

2.0

3.0

0.5

4.5

1.5

2.5

3.5

5.0

CC5

= V

CC3

= V

CCA

RST PIN LOADED WITH
10M

TO GND

= 25

Power-Fail Response Time
vs Temperature

TIME (20ns/DIV)

VOLTAGE (1V/DIV)

1536 G14

CC5

RST

LTC1536

CTIO

CC3

(Pin 1): 3.3V Sense Input and Power Supply Pin for

the IC. Bypass to ground with

0.1

F ceramic capacitor.

CC5

(Pin 2): 5V Sense Input. Used as gate drive for RST

output FET when the voltage on V

CC5

is greater than the

voltage on V

CC3

CCA

(Pin 3): 1V Sense, High Impedance Input. Can be

used as a logic input with a 1V threshold. If unused it can
be tied to either V

CC3

or V

CC5

GND (Pin 4): Ground.

RST (Pin 5): Reset Logic Output. Active high CMOS logic
output, drives high to V

CC3

, buffered compliment of RST.

An external pull-down on the RST pin will drive this pin high.

RST (Pin 6): Reset Logic Output. Active low, open-drain
logic output with weak pull-up to V

CC3

. Can be pulled up

greater than V

CC3

when interfacing to 5V logic.

CC3

SOFT RESET

RESET

CCA

CC5

POWER
DETECT

PBR

SRST

GND

REF

PBR

TIMER

200ms
RESET

GENERATOR

POWER

DETECT/

GATE DRIVE

CC3

RST

CC3

CC5

RST

CC3

FAST

SLOW

FAST

SLOW

CC3

TO POWER DETECT
AND V

INTERNAL

1326 BD

BLOCK DIAGRA

Asserted when one or more of the supplies are below trip
thresholds and held for 200ms after all supplies become
valid. Also asserted after PBR is held low for more than two
seconds and for an additional 200ms after PBR is released.

SRST (Pin 7): "Soft" Reset. Active low, open-drain logic
output with weak pull-up to V

CC3

. Can be pulled up greater

than V

CC3

when interfacing to 5V logic. Asserted for 100

after PBR is held low for less than two seconds and released.

PBR (Pin 8): Pushbutton Reset. Active low logic input with
weak pull-up to V

CC3

. Can be pulled up greater than V

CC3

when interfacing to 5V logic. When asserted for less than
two seconds, outputs a soft reset 100

s pulse on the SRST

pin. When PBR is asserted for greater than two seconds,
the RST output is forced low and remains low until 200ms
after PBR is released.

LTC1536

TI I G DIAGRA S

Monitor Timing

Pushbutton Reset Function Timing

t < t

RST

SRST

1536 TD02

PBR

RST

SRST

RST

1536 TD01

RTX

CCX

RST

FAIL

Fast Undervoltage Detect

FAIL

500mV

1536 TD03

CC3 OR

CC5

RTX

SLEW RATE

0.1V/

RST

300mV

1536 TD04

CC5

FALL TIME

10ns, V

CC3

= 3.3V

RST

3.3V

Power-Fail Detect

APPLICATIO

S I

FOR

ATIO

Operation

The LTC1536 is a low power, high accuracy triple supply
monitoring circuit. This reset generator has two basic
functions: generation of a reset when power supplies are
out of range, and generation of a reset or "soft" reset when
the reset button is pushed. The LTC1536 has the added
feature that when the reset supplies are grossly undervolt-
age there is a very short delay from undervoltage detect to
assertion of RST.

Supply Monitoring

All three V

inputs must be above predetermined thresh-

olds for 200ms before the reset output is released. The
LTC1536 will assert reset during power-up, power-down
and brownout conditions on any one or more of the V

inputs.

On power-up, either the V

CC5

or V

CC3

pin can power the

drive circuits for the RST pin. This ensures that RST will

be low when either V

CC5

or V

CC3

reaches 1V. As long as

any one of the V

inputs is below its predetermined

threshold, RST will stay a logic low. Once all of the V

inputs rise above their thresholds, an internal timer is
started and RST is released after 200ms. RST outputs the
inverted state of what is seen on RST.

RST is reasserted whenever any one of the V

inputs

drops below its predetermined threshold and remains
asserted until 200ms after all of the V

inputs are above

their thresholds.

On power-down, once any of the V

inputs drops below

its threshold, RST is held at a logic low. A logic low of 0.4V
is guaranteed until V

CC3

and V

CC5

drops below 1V.

Pushbutton Reset

The LTC1536 provides a pushbutton reset input pin. The
PBR input has an internal pull-up current source to V

CC3

If the PBR pin is not used it can be left floating.

LTC1536

When the PBR is pulled low for less than t

(

2 sec), a

narrow (100

s typ) soft reset pulse is generated on the

SRST output pin after the button is released. The push-
button circuitry contains an internal debounce counter
which delays the output of the soft reset pulse by typically
20ms. This pin can be OR-tied to the RST pin and issue
what is called a "soft" reset. The SRST thereby resets the
microprocessor without interrupting the DRAM refresh
cycle. In this manner DRAM information remains undis-
turbed. Alternatively, SRST may be monitored by the
processor to initiate a software-controlled reset.

When the PBR pin is held low for longer than t

(

2 sec),

a standard reset is generated. Once the 2-second period
has elapsed, a reset signal is produced by the pushbutton
logic, thereby clearing the reset counter. Once the PBR
pin is released, the reset counter begins counting the
reset period (200ms nominal). Consequently, the reset
outputs remain asserted for approximately 200ms after
the button is released.

Fast Undervoltage for PCI Applications

The LTC1536 is designed for PCI Local Bus applications
that require reset to be asserted quickly in response to one
or both of the power supply rails (5V and 3.3V) going out
of spec. The spec for t

FAIL

and t

are met with enough

margin to give the designer the ability to add follow-on
logic as needed by system requirements. The V

CCA

pin can

be used to monitor the "power good" signal and keep reset
applied until both supplies are in spec and the power good
signal is high.

Glitch Immunity and Fast Undervoltage Detection

The LTC1536 achieves its high speed characteristics while
maintaining glitch immunity by using two sets of com-
parators. The V

CC5

and V

CC3

sense inputs each have two

comparators set at different thresholds. A slow, very
accurate comparator monitors the supply for precision
undervoltage detection. In parallel, but with a threshold
250mV lower than the precision threshold, is a very fast
comparator that detects when the supply is quickly going
out of specification. Because the fast comparator thresh-
old is set 250mV above the PCI specification, typical
values for t

FAIL

can be negative.

3V or 5V Power Detect/Gate Drive

The LTC1536 for the most part is powered internally from
the V

CC3

pin. The exception is at the gate drive of the output

FET on the RST pin. On the gate to this FET is power detect
circuitry used to detect and drive the gate from either the
3.3V pin or the 5V pin, whichever pin has the highest
potential. This ensures the part pulls the RST pin low as
soon as either input pin is

1V.

Extended ESD Tolerance of the PBR Input Pin

The PBR pin is susceptible to ESD since it can be brought
out to a front panel in normal applications. The ESD
tolerance of this pin can be increased by adding a resistor
in series with the PBR pin. A 10k resistor can increase the
ESD tolerance of the PBR pin to approximately 10kV. The
PBR's internal pull-up current of 7

A typical means there

is only 70mV (150mV max) dropped across the resistor.

APPLICATIO

S I

FOR

ATIO

TYPICAL APPLICATIO

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

PCI

LOCAL

BUS

0.1

3.3V SUPPLY

RESET

5V SUPPLY

1536 TA08

0.1

ONBOARD

DEVICE

PCI Expansion Board RST Generation

Dual Supply Monitor (3.3V and 5V, V

CCA

Input

Monitoring "Power Good")

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

3.3V

SYSTEM RESET

PWR GOOD

1536 TA04

LTC1536

TYPICAL APPLICATIO

Triple Supply Monitor (3.3V, 5V and Adjustable)

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

3.3V

SYSTEM RESET

100k

1536 TA09

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

3.3V

SYSTEM RESET

*OPTIONAL RESISTOR EXTENDS
ESD TOLERANCE OF PBR INPUT
8kV TO 10kV

1536 TA03

ADJUSTABLE SUPPLY

OR DC/DC FEEDBACK

DIVIDER

10k*

PUSHBUTTON

RESET

SRST Tied to RST and OR-Tying Other Sources to RST to

Generate Reset and Reset

4.7k

SRST

3.3V

LTC1536

PUSHBUTTON

RESET

1536 TA05

OTHER OPEN DRAIN

RESET SOURCES

OR-TIED TO RESET

PBR

RST

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

3.3V

SYSTEM RESET

22.1k
1%

1536 TA07

35.7k
1%

LTC1435

ADJUSTABLE

RESET TRIP

THRESHOLD 2.74V

2.9V

2.8k
1%

OSENSE

Using V

CCA

Tied to DC/DC Feedback Divider

RESET Valid for V

CC3

Down to 0V

in a Dual Supply Application

LTC1536

Dimensions in inches (millimeters) unless otherwise noted.

PACKAGE DESCRIPTIO

MS8 Package

8-Lead Plastic MSOP

(LTC DWG # 05-08-1660)

MSOP (MS8) 1197

* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,

PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

0.021

0.006

(0.53

0.015)

TYP

SEATING

PLANE

0.007

(0.18)

0.040

0.006

(1.02

0.15)

0.012

(0.30)

REF

0.006

0.004

(0.15

0.102)

0.034

0.004

(0.86

0.102)

0.0256

(0.65)

TYP

0.192

0.004

(4.88

0.10)

7 6

0.118

0.004*

(3.00

0.102)

0.118

0.004**

(3.00

0.102)

LTC1536

Dimensions in inches (millimeters) unless otherwise noted.

PACKAGE DESCRIPTIO

S8 Package

8-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

0.150 0.157**

(3.810 3.988)

0.189 0.197*

(4.801 5.004)

0.228 0.244

(5.791 6.197)

0.016 0.050
0.406 1.270

0.010 0.020

(0.254 0.508)

TYP

0.008 0.010

(0.203 0.254)

SO8 0996

0.053 0.069

(1.346 1.752)

0.014 0.019

(0.355 0.483)

0.004 0.010

(0.101 0.254)

0.050

(1.270)

TYP

DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

LTC1536

LINEAR TECHNOLOGY CORPORATION 1997

1536f, sn1536a LT/TP 0498 4K ˇ PRINTED IN THE USA

TYPICAL APPLICATIO

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900

FAX: (408) 434-0507

TELEX: 499-3977

www.linear-tech.com

PART NUMBER

DESCRIPTION

COMMENTS

LTC690

5V Supply Monitor, Watchdog Timer and Battery Backup

4.65V Threshold

LTC694-3.3

3.3V Supply Monitor, Watchdog Timer and Battery Backup

2.9V Threshold

LTC699

5V Supply Monitor and Watchdog Timer

4.65V Threshold

LTC1232

5V Supply Monitor, Watchdog Timer and Pushbutton Reset

4.37V/4.62V Threshold

LTC1326

Micropower Precision Triple Supply Monitor

4.725V, 3.118V, 1V Thresholds (

0.75%)

LTC1326-2.5

Micropower Precision Triple Supply Monitor

2.363V, 3.118V, 1V Thresholds (

0.75%)

RELATED PARTS

Quad Supply Monitor:

12V: Undervoltage, Overvoltage

5V: Undervoltage, Overvoltage

3.3V: Undervoltage, Overvoltage

 12V: Undervoltage

PWR GOOD

12V

LTC1444

1.21M

1.21M
1%

2.37M
1%

3.3V

0.3V

12V

10%

1.05M
1%

102k
1%

100k

0.1

OPTIONAL

4.02M

HYST

1536 TA07

9.31M

1.21M

REF

1.221V

10.7M

SYSTEM
RESET

CC3

CC5

CCA

GND

PBR

SRST

RST

LTC1536

Part Number LTC1536