Datasheet LTC1536 Datasheet (Linear Technology)

FEATURES

■

Simultaneously Monitors 5V, 3.3V and Adjustable Inputs

■

Guaranteed Threshold Accuracy: ±0.75%

■

Low Supply Current: 100µA

■

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

■

Meets PCI t

■

8-Pin SO and MSOP Packages

Timing Specifications Rev 2.1

FAIL

≥ 1V or V

CC3

U

APPLICATIO S

■

PCI-Based Systems

■

Desktop Computers

■

Notebook Computers

■

Intelligent Instruments

■

Portable Battery-Powered Equipment

■

Network Servers

CC5

≥ 1V

LTC1536

Precision Triple Supply Monitor

for PCI Applications

U

DESCRIPTIO

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 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

down to 1V. The 100µA typical supply current

CC3

makes the LTC1536 ideal for power-conscious systems. A manual pushbutton reset input provides the ability to

generate a very narrow “soft” reset pulse (100µs 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.

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

timing specification. Tight 0.75%

FAIL

TYPICAL APPLICATIO

Motherboard PCI RST Generation

3.3V ±0.3V

5V ±5%

PWR GOOD

0.1µF

LTC1536

1

V

CC3

2

V

CC5

3

V

CCA

4

GND

SELECTED TO MEET RISE TIME

R

PU

SLEW RATE REQUIREMENTS (1k MIN)

U

PBR

SRST

RST RST

PUSHBUTTON

RESET

8 7 6 5

R

RST

Power Fail Waveform

5V Dropping Below 3.3V by 300mV

V

= 5V TO 3V STEP

CC5

= V

RST

CCA

= 3.3V

CC3

1536 TA02

V

CC3

PU

PCI LOCAL BUS

1536 TA01

5

4

3

2

VOLTAGE (1V/DIV)

1

0

4.7k PULL-UP FROM RST TO V

V

CC5

TIME (20ns/DIV)

1

LTC1536

1

2

3

4

8

7

6

5

TOP VIEW

S8 PACKAGE

8-LEAD PLASTIC SO

V

CC3

V

CC5

V

CCA

GND

PBR

SRST

RST

1 2 3 4

V

CC3

V

CC5

V

CCA

GND

8 7 6 5

PBR SRST RST RST

TOP VIEW

MS8 PACKAGE

8-LEAD PLASTIC MSOP

A

W

O

LUTEXI TIS

S

A

WUW

U

ARB

G

(Notes 1, 2)

Terminal Voltage

V

, V

CC3

CC5

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

CCA

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

RST ......................................... –0.3V to V

CC3

+ 0.3V

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

WU

/

= 125°C, θ

O

RDER I FOR ATIO

ORDER

PART NUMBER

LTC1536CMS8

MS8 PART MARKING

= 160°C/W

JA

LTBV

PACKAGE

T

JMAX

Operating Temperature Range

LTC1536C .............................................. 0°C to 70°C

LTC1536I............................................ –40°C to 85°C

Storage Temperature Range ................ –65°C to 150°C

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

U

ORDER

PART NUMBER

LTC1536CS8 LTC1536IS8

S8 PART MARKING

T

JMAX

= 125°C, θ

= 150°C/W

JA

1536 1536I

Consult factory for Military grade parts.

ELECTRICAL CHARACTERISTICS

V

= 3.3V, V

CC3

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

RT3

V

RT5

V

RTA

V

CC

I

VCC3

I

VCC5

I

VCCA

t

RST

t

SRST

t

UV

2

= 5V, V

CC5

Reset Threshold V

V

or V

CC3

V

Supply Current PBR = V

CC3

V

Input Current V

CC5

V

Input Current V

CCA

Reset Pulse Width RST Low with 10kΩ Pull-Up to V

Soft Reset Pulse Width SRST Low with 10kΩ Pull-Up to V VCC Undervoltage Detect to RST V

= V

CCA

Operating Voltage RST in Correct Logic State ● 17V

CC5

, TA = 25°C unless otherwise noted.

CC3

CC5

CCA

0°C ≤ TA ≤ 70°C ● 2.962 2.985 3.000 V –40°C ≤ T

0°C ≤ TA ≤ 70°C ● 4.687 4.725 4.750 V –40°C ≤ T

0°C ≤ TA ≤ 70°C ● 0.992 1.000 1.007 V –40°C ≤ T

= 5V ● 10 20 µA

CC5

= 1V, 0°C ≤ TA ≤ 70°C ● –5 0 5 nA

CCA

V

= 1V, –40°C ≤ TA ≤ 85°C ● –15 0 15 nA

CCA

0°C to 70°C ● 140 200 280 ms –40°C to 85°C

, V

CC5

Threshold V

≤ 85°C ● 2.925 2.985 3.008 V

A

≤ 85°C ● 4.625 4.725 4.762 V

A

≤ 85°C ● 0.980 1.000 1.007 V

A

CC3

or V

CC3

Less Than Reset 13 µs

CCA

by 1%

RT

● 100 200 µA

CC3

● 140 200 300 ms

● 50 100 200 µs

CC3

LTC1536

ELECTRICAL CHARACTERISTICS

V

= 3.3V, V

CC3

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

PBR

V

IL

V

IH

t

PW

t

DB

t

PB

V

OL

V

OH

t

PHL

t

PLH

t

FAIL

t

PF

= 5V, V

CC5

CCA

= V

, TA = 25°C unless otherwise noted.

CC3

PBR Pull-Up Current PBR = 0V, 0°C ≤ TA ≤ 70°C ● 3710 µA

PBR = 0V, –40°C ≤ T

≤ 85°C ● 3715 µA

A

PBR, RST Input Low Voltage ● 0.8 V PBR, RST Input High Voltage ● 2V PBR Min Pulse Width ● 40 ns PBR Debounce Deassertion of PBR Input to SRST ● 20 35 ms

Output (PBR Pulse Width = 1µs)

PBR Assertion Time for Transition PBR Held Less Than VIL, 0°C to 70°C ● 1.4 2.0 2.8 s from Soft to Hard Reset Mode PBR Held Less Than V

RST Output Voltage Low I

SRST Output Voltage Low I RST Output Voltage Low I RST Output Voltage High (Note 3) I SRST Output Voltage High (Note 3) I RST Output Voltage High I Propagation Delay RST to RST C

= 5mA ● 0.15 0.4 V

SINK

I

= 100µAV

SINK

≤ 70°CV

0°C ≤ T

A

I

= 100µAV

SINK

–40°C ≤ T

SINK

SOURCE

RST

≤ 85°CV

A

= 2.5mA ● 0.15 0.4 V = 2.5mA ● 0.15 0.4 V

= 1µA ● V = 1µA ● V = 600µA ● V

= 20pF 25 ns

, –40°C to 85°C ● 1.4 2.0 3.0 s

IL

CC3 CC3

V

CC3

CC3 CC3

V

CC3

= 1V, V = 0V, V = 1V, V

= 1.1V, V = 0V, V = 1.1V, V

= 0V ● 0.05 0.4 V

CC5

= 1V ● 0.05 0.4 V

CC5

= 1V ● 0.05 0.4 V

CC5

= 0V ● 0.05 0.4 V

CC5

= 1.1V ● 0.05 0.4 V

CC5

= 1.1V ● 0.05 0.4 V

CC5

– 1 V

CC3

– 1 V

CC3

– 1 V

CC3

High Input to Low Output Propagation Delay RST to RST C

= 20pF 45 ns

RST

Low Input to High Output V

or V

CC5

0.5V Undervoltage V

CC3

Drops Below 4.25V or V

CC5

Drops ● 150 450 ns

CC3

to RST (Note 4) Below 2.5V (Note 5) V

< (V

CC5

– 300mV) RST (Note 4) V

CC3

Drops Below V

CC5

By 300mV ● 50 90 ns

CC3

(Note 6)

● denotes specifications which apply over the full operating

The 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

of 6µA. However, external pull-up resistors may be used when faster

CC3

rise times are required.

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

Note 5: V V

Note 6: V V

CC3

– 500mV to RST at 1.5V.

RTX

CC5

= (V

CC5

CC3

.

FAIL

or V

falling at –0.1V/µs, time measured from

CC5

falling from 5V to 3V in ≤10ns, time measured from – 300mV) to RST at 1.5V.

3

LTC1536

INPUT VOLTAGE (V)

0.8

–3

INPUT CURRENT (nA)

–2

–1

0

1

0.9 1.0

1.1

1.2

1536 G03

2

3

0.85 0.95

1.05

1.15

TA = 25°C

UW

TYPICAL PERFORMANCE CHARACTERISTICS

I

vs Temperature

VCC3

140

120

100

80

(µA)

60

VCC3

I

40

20

0

–45

V

–5

–25

TEMPERATURE (°C)

Threshold Voltage

CC5

vs Temperature

4.750

4.745

(V)

4.740

RT5

4.735

4.730

4.725

4.720

4.715

THRESHOLD VOLTAGE, V

4.710

CC5

V

4.705

4.700 –60

–40 0

–20

TEMPERATURE (°C)

35

15

20

55

75

1536 G01

80

60

40

100

1536 G04

I

vs Temperature

VCC5

20.0

17.5

15.0

12.5

(µA)

10.0

VCC5

I

7.5

5.0

2.5

0

–45

V

CC3

–5

–25

TEMPERATURE (°C)

Threshold Voltage

vs Temperature

3.010

3.005

(V)

3.000

RT3

2.995

2.990

2.985

2.980

2.975

THRESHOLD VOLTAGE, V

2.970

CC3

V

2.965

2.960 –60

–20 20

–40 80

TEMPERATURE (°C)

35

15

0 40 100

55

60

75

1536 G02

1536 G05

V

Input Current

CCA

vs Input Voltage

V

Threshold Voltage

CCA

vs Temperature

1.005

1.004

(V)

1.003

RTA

1.002

1.001

1.000

0.999

0.998

THRESHOLD VOLTAGE, V

0.997

CCA

V

0.996

0.995 –60

–40 0

–20

TEMPERATURE (°C)

80

20

60

40

100

1536 G06

225

220

(ms)

215

RST

210

205

200

RESET PULSE WIDTH, t

195

190

4

Reset Pulse Width vs Temperature

–50

–25 0

TEMPERATURE (°C)

50 100

25 75

1536 G07

“Soft” Reset Pulse Width vs Temperature

112.5

110.0

(µs)

SRST

107.5

105.0

102.5

100.0

97.5

SOFT RESET PULSE WIDTH, t

95.0 –50

–25 0

TEMPERATURE (°C)

50 100

25 75

1536 G08

PBR Assertion Time to Reset vs Temperature

2.25

(SEC)

2.20

PB

2.15

2.10

2.05

2.00

1.95

PBR ASSERTION TIME TO RESET, t

1.90 –50

–25 0

25 75

TEMPERATURE (°C)

50 100

1536 G09

UW

TYPICAL PERFORMANCE CHARACTERISTICS

V

Typical Transient Duration

CC3

vs Reset Comparator Overdrive

50 45 40 35 30 25 20 15 10

TYPICAL TRANSIENT DURATION (µs)

5 0

0.001

V

RESET COMPARATOR OVERDRIVE, V

CC3

0.01 0.1 1

RESET OCCURS ABOVE CURVE

– V

RT3

1536 G10

CC3

(V)

V

Typical Transient Duration

CC5

vs Reset Comparator Overdrive

45

40

35

30

25

20

15

10

TYPICAL TRANSIENT DURATION (µs)

5

0

0.001

V

RESET COMPARATOR OVERDRIVE, V

CC5

0.01 0.1 1

RESET OCCURS ABOVE CURVE

RT5

– V

1536 G11

CC5

(V)

LTC1536

V

Typical Transient Duration

CCA

vs Reset Comparator Overdrive

40

35

30

25

20

15

10

5

TYPICAL TRANSIENT DURATION (µs)

0

0.001 RESET COMPARATOR OVERDRIVE, V

V

CCA

0.01 0.1 1

RESET OCCURS ABOVE CURVE

– V

RTA

1536 G12

CCA

(V)

RST Output Voltage vs Supply Voltage

5.0 V

= V

CC5

CC3

4.5

4.7k PULL-UP FROM RST TO V TA = 25°C

4.0

3.5

3.0

2.5

2.0

1.5

RST OUTPUT VOLTAGE (V)

1.0

0.5

0

0.5 4.5

CCA

1.0

1.5

SUPPLY VOLTAGE, VCC (V)

2.0

2.5

3.0

Undervoltage Response Time vs Temperature

DEVICE THRESHOLD

PCI SPEC

85° –40°

25°

3.5

CC5

4.0

1536 G13

V

CC3

5.0

RST Output Voltage vs Supply Voltage

5.0 V

= V

CC5

4.5 RST PIN LOADED WITH

10MΩ TO GND

4.0 T

A

3.5

3.0

2.5

2.0

1.5

RST OUTPUT VOLTAGE (V)

1.0

0.5

0

0.5 4.5

= V

CC3

CCA

= 25°C

1.0

1.5

2.0

2.5

SUPPLY VOLTAGE, VCC (V)

Power-Fail Response Time vs Temperature

V

CC5

3.0

3.5

4.0

5.0

1536 G16

VOLTAGE (500mV/DIV)

V

FALLING

CC3

FROM 3.3V TO

2.3V AT (–0.1V/µs) TIME (1µs/DIV)

t

FAIL

MARGIN

SPEC

RST

1536 G15

VOLTAGE (1V/DIV)

–40°

85°

25°

RST

TIME (20ns/DIV)

1536 G14

5

LTC1536

UUU

PIN FUNCTIONS

V

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

CC3

the IC. Bypass to ground with ≥0.1µF ceramic capacitor.

V

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

CC5

output FET when the voltage on V voltage on V

V

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

CCA

CC3

.

is greater than the

CC5

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

, buffered compliment of RST.

CC3

An external pull-down on the RST pin will drive this pin high. RST (Pin 6):

logic output with weak pull-up to V greater than V

Reset Logic Output. Active low, open-drain

. Can be pulled up

CC3

when interfacing to 5V logic.

CC3

W

BLOCK DIAGRAM

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 than V

when interfacing to 5V logic. Asserted for 100µs

CC3

. Can be pulled up greater

CC3

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

. Can be pulled up greater than V

CC3

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

CC3

CC5

CCA

8PBR

1V

2V

3V

4GND

TO

POWER

DETECT

V

CC3

7µA

TO POWER DETECT

INTERNAL

AND V

CC

REF

–

FAST

+

–

SLOW

+

FAST

–

FAST

+

–

SLOW

+

–

SLOW

+

PBR

TIMER

SOFT RESET

RESET

200ms RESET

GENERATOR

V

CC3

POWER

DETECT/

GATE DRIVE

V

CC5

6µA

V

CC3

7 SRST

V

CC3

6 RST

V

CC3

5

RST

6

1326 BD

WWU

TI I G DIAGRA S

VCC Monitor Timing Pushbutton Reset Function Timing

LTC1536

V

CCX

RST

RTX

V

CC3 OR

V

RST

CC5

t

Fast Undervoltage Detect

FAIL

SLEW RATE ≤0.1V/µs

V

RTX

t

FAIL

U

t

RST

500mV

WUU

1536 TD03

APPLICATIONS INFORMATION

1536 TD01

PBR

RST

SRST

t < t

V

CC5

RST

PB

t

DB

t

SRST

t

PB

t

RST

1536 TD02

Power-Fail Detect

3.3V

FALL TIME ≤ 10ns, V

t

PF

CC3

300mV

= 3.3V

1536 TD04

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 undervoltage there is a very short delay from undervoltage detect to assertion of RST.

Supply Monitoring

All three VCC inputs must be above predetermined thresholds 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

CC

inputs. On power-up, either the V

CC5

or V

pin can power the

CC3

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

be low when either V

CC5

or V

reaches 1V. As long as

CC3

any one of the VCC inputs is below its predetermined threshold, RST will stay a logic low. Once all of the V

CC

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 VCC inputs drops below its predetermined threshold and remains asserted until 200ms after all of the VCC inputs are above their thresholds.

On power-down, once any of the VCC 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

drops below 1V.

CC5

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.

7

LTC1536

U

WUU

APPLICATIONS INFORMATION

When the PBR is pulled low for less than tPB (≈2 sec), a narrow (100µs typ) soft reset pulse is generated on the SRST output pin after the button is released. The pushbutton 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 undisturbed. Alternatively, SRST may be monitored by the processor to initiate a software-controlled reset.

When the PBR pin is held low for longer than tPB ( ≈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 margin to give the designer the ability to add follow-on logic as needed by system requirements. The V 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.

and tPF are met with enough

FAIL

CCA

pin can

Glitch Immunity and Fast Undervoltage Detection

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

CC5

and V

sense inputs each have two

CC3

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 threshold is set 250mV above the PCI specification, typical values for t

can be negative.

FAIL

3V or 5V Power Detect/Gate Drive

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

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

CC3

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 7µA typical means there is only 70mV (150mV max) dropped across the resistor.

U

TYPICAL APPLICATIONS N

PCI Expansion Board RST Generation

3.3V SUPPLY

PCI

LOCAL

BUS

0.1µF

5V SUPPLY

0.1µF

RESET

LTC1536

1

V

CC3

2

V

CC5

3

V

CCA

4

GND

PBR

SRST

RST RST

8 7 6 5

8

ONBOARD

DEVICE

1536 TA08

Dual Supply Monitor (3.3V and 5V, V

Monitoring “Power Good”)

LTC1536

3.3V

PWR GOOD

1

V

CC3

5V

2

V

CC5

3

V

CCA

4

GND

PBR

SRST

RST RST

8 7 6

SYSTEM RESET

5

CCA

Input

1536 TA04

U

TYPICAL APPLICATIONS N

LTC1536

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

ADJUSTABLE SUPPLY

OR DC/DC FEEDBACK

DIVIDER

LTC1536

3.3V

R1

1 2

5V

3 4

R2

PBR

V

CC3

SRST

V

CC5

RST

V

CCA

GND

RST

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

10k*

8 7 6 5

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

Generate Reset and Reset

PUSHBUTTON

8

6µA

V

CC3

PBR

SRST

RST

3.3V

4.7k

7

6

5

RESET

OTHER OPEN DRAIN

RESET SOURCES

OR-TIED TO RESET

LTC1536

6µA

PUSHBUTTON

RESET

SYSTEM RESET

1536 TA03

3.3V 5V

Using V

LTC1435

V

OSENSE

ADJUSTABLE

RESET TRIP

THRESHOLD 2.74V

RESET Valid for V

Down to 0V

CC3

in a Dual Supply Application

LTC1536

1

V

CC3

2

V

CC5

3

V

CCA

4

GND

Tied to DC/DC Feedback Divider

CCA

2.9V

35.7k 1%

6

2.8k 1%

22.1k 1%

3.3V

SRST

5V

PBR

RST RST

8 7 6 5

1

V

CC3

2

V

CC5

3

V

CCA

4

GND

100k

SYSTEM RESET

LTC1536

SRST

PBR

RST RST

1536 TA09

8 7 6 5

SYSTEM RESET

1536 TA07

1536 TA05

9

LTC1536

(

PACKAGE DESCRIPTION

U

Dimensions in inches (millimeters) unless otherwise noted.

MS8 Package

8-Lead Plastic MSOP

(LTC DWG # 05-08-1660)

0.118 ± 0.004* (3.00 ± 0.102)

8

7

6

5

0.192 ± 0.004

(4.88 ± 0.10)

12

0.040

± 0.006

SEATING

PLANE

(1.02 ± 0.15)

0.012 (0.30)

0.0256

REF

(0.65)

0.152mm) PER SIDE

TYP

0.007 (0.18)

0.021

± 0.006

(0.53 ± 0.015)

* 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"

° – 6° TYP

0

0.118 ± 0.004**

4

3

0.034 ± 0.004

(0.86 ± 0.102)

(3.00 ± 0.102)

0.006 ± 0.004

(0.15 ± 0.102)

MSOP (MS8) 1197

10

PACKAGE DESCRIPTION

U

Dimensions in inches (millimeters) unless otherwise noted.

S8 Package

8-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

0.189 – 0.197* (4.801 – 5.004)

7

8

5

6

LTC1536

0.228 – 0.244

(5.791 – 6.197)

0.010 – 0.020

(0.254 – 0.508)

0.008 – 0.010

(0.203 – 0.254)

*

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

×

°

45

0.016 – 0.050

0.406 – 1.270

0°– 8° TYP

0.053 – 0.069

(1.346 – 1.752)

0.014 – 0.019

(0.355 – 0.483)

0.150 – 0.157** (3.810 – 3.988)

1

3

2

4

0.004 – 0.010

(0.101 – 0.254)

0.050

(1.270)

TYP

SO8 0996

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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

11

LTC1536

U

TYPICAL APPLICATIONS N

Quad Supply Monitor:

12V: Undervoltage, Overvoltage

5V: Undervoltage, Overvoltage

3.3V: Undervoltage, Overvoltage

–12V: Undervoltage

3.3V ±0.3V

5V ±5%

12V ±5%

–12V ±10%

4.02M 1%

9.31M 1%

10.7M 1%

2.37M 1%

1.21M 1%

1.21M

1M

1.21M 1%

10

11

12

13

14

4

5

6

7

8

LTC1444

–

+

–

+

–

+

–

+

HYST

A

B

C

D

REF

1.221V

3

2

1

16

15

9

1536 TA07

12V

0.1

1.05M 1%

102k 1%

µ

F

PWR GOOD

OPTIONAL

100k

LTC1536

1

V

CC3

5V

2

V

CC5

3

V

CCA

4

GND

PBR

SRST

RST RST

8 7 6 5

SYSTEM RESET

RELATED PARTS

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%)

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

 LINEAR TECHNOLOGY CORPORATION 1997

12

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417 ● (408) 432-1900 FAX: (408) 434-0507

●

TELEX: 499-3977 ● www.linear-tech.com

Datasheet LTC1536 Datasheet (Linear Technology)

Specifications and Main Features

Frequently Asked Questions

User Manual