1

LTC2901

2901is sn2901

Programmable Quad Supply

Monitor with Adjustable Reset

and Watchdog Timers

June 2002

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.

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Simultaneously Monitors Four Supplies

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16 User Selectable Combinations of 5V, 3.3V, 3V,

2.5V, 1.8V, 1.5V and/or

±Adjustable Voltage

Thresholds

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Guaranteed Threshold Accuracy:

±1.5% of

Monitored Voltage Over Temperature

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Low Supply Current: 43

µA Typ

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Adjustable Reset Time

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Adjustable Watchdog Time

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Open-Drain RST Output (LTC2901-1)

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Push-Pull RST Output (LTC2901-2)

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Individual Nondelayed Monitor Output for Each Supply

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Power Supply Glitch Immunity

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The LTC

systems with up to four supply voltages. One of 16 preset

or adjustable voltage monitor combinations can be se-

lected using an external resistor divider connected to the

program pin. The preset voltage thresholds are accurate

to 1.5% over temperature. All four voltage comparator

outputs are connected to separate pins for individual

supply monitoring.

The reset and watchdog delay times are adjustable using

external capacitors. Tight voltage threshold accuracy and

glitch immunity ensure reliable reset operation without

false triggering. The RST output is guaranteed to be in the

an open-drain RST output, while the LTC2901-2 has a

push-pull RST output.

The 43

µA supply current makes the LTC2901 ideal for

power conscious systems and it may be configured to

monitor less than four inputs. The parts are available in

the 16-lead narrow SSOP package.

Quadruple Supply Monitor (5V, 3.3V, 2.5V, 1.8V)

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Desktop and Notebook Computers

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Multivoltage Systems

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Telecom Equipment

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Portable Battery-Powered Equipment

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Network Servers

Final Electrical Specifications

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

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

V1

V2

COMP1

COMP2

COMP3

COMP4

WDI

WDO

RST

GND

10

11

R1

59k

1%

R3

10k

POWER

GOOD

R2

40.2k

1%

12

6

7

8

15

1

16

2

13

3

14

4

9

5

47nF

47nF

C2

0.1

µF

C1

0.1

µF

V4

V3

LTC2901-2

CWT

CRT

2901 TA01

DC/DC

CONVERTER

1.8V

2.5V

3.3V

5V

SYSTEM

LOGIC