1

LTC2902

2902f

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

Programmable Quad Supply

Monitor with Adjustable Reset Timer

and Supply Tolerance

s

Simultaneously Monitors Four Supplies

s

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

2.5V, 1.8V, 1.5V and/or

±Adjustable Voltage

Thresholds

s

Guaranteed Threshold Accuracy:

±1.5% of Monitored

Voltage Over Temperature

s

Selectable Supply Tolerance: 5%, 7.5%,

10%, 12.5% Below Monitored Voltage

s

Low Supply Current: 43

µA Typ

s

Adjustable Reset Time

s

RESET Disable Pin for Margining Applications

s

Open-Drain RST Output (LTC2902-1)

s

Push-Pull RST Output (LTC2902-2)

s

Individual Nondelayed Monitor Outputs for Each Supply

s

Power Supply Glitch Immunity

s

The LTC

tems with up to four supply voltages. One of 16 preset or

adjustable voltage monitor combinations can be selected

using an external resistor divider connected to the pro-

gram pin. The preset voltage thresholds are digitally pro-

grammable to 5%, 7.5%, 10% or 12.5% below the nomi-

nal operating voltage, and are accurate to 1.5% over tem-

perature. All four voltage comparator outputs are con-

nected to separate pins for individual supply monitoring.

The reset delay time is adjustable using an external

capacitor. Tight voltage threshold accuracy and glitch

immunity ensure reliable reset operation without false

triggering. The RST output is guaranteed to be in the

during supply margin testing. The LTC2902-1 features

an open-drain RST output, while the LTC2902-2 has a

push-pull RST output.

The 43

µAsupplycurrentmakestheLTC2902idealforpower

conscious systems and the part may be configured to

monitor less than four inputs. The LTC2902-1/LTC2902-2

are available in the 16-lead narrow SSOP package.

Quad Supply Monitor with Adjustable Tolerance (5V, 3.3V, 2.5V, 1.8V)

s

Desktop and Notebook Computers

s

Multivoltage Systems

s

Telecom Equipment

s

Portable Battery-Powered Equipment

s

Network Servers

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

V1

V2

COMP1

COMP2

COMP3

COMP4

RST

RDIS

T0

T1

GND

10

11

R1

59k

1%

R3

10k

POWER

GOOD

R2

40.2k

1%

12

7

9

8

6

15

1

16

2

13

3

14

4

5

47nF

C2

0.1

µF

C1

0.1

µF

V4

V3

LTC2902-2

CRT

MARGIN

TOLERANCE = 5%

2902 TA01

DC/DC

CONVERTER

1.8V

2.5V

3.3V

5V

SYSTEM

LOGIC