LTC2938/LTC2939

1

293839ff

V1 (V)

V2 (V)

V3 (V)

V4 (V)

V5 (V)

V6 (V)

5

3.3

2.5

1.8

ADJ

ADJ

5

3.3

2.5

ADJ

ADJ

ADJ

5

3.3

1.8

ADJ

ADJ

ADJ

5

3.3

ADJ

ADJ

ADJ

ADJ

5

3.3

ADJ

–

ADJ

ADJ

ADJ

3.3

2.5

1.8

1.5

ADJ

ADJ

3.3

2.5

1.8

ADJ

ADJ

ADJ

3.3

1.8

1.5

1.2

ADJ

ADJ

3.3

1.8

1.5

ADJ

ADJ

ADJ

3.3

1.8

1.2

ADJ

ADJ

ADJ

3.3

2.5

ADJ

ADJ

ADJ

ADJ

3.3

2.5

ADJ

–ADJ

ADJ

ADJ

3.3

1.8

ADJ

ADJ

ADJ

ADJ

3.3

1.8

ADJ

–ADJ

ADJ

ADJ

3.3

1.5

ADJ

ADJ

ADJ

ADJ

3.3

1.2

ADJ

ADJ

ADJ

ADJ

TYPICAL APPLICATION

DESCRIPTION

Configurable 4- and 6-Supply

Monitors with Watchdog Timer

for systems with up to four or six supply voltages that need

watchdog supervision. One of sixteen preset or adjustable

voltage monitor combinations can be selected using an

external resistive divider connected to the program input.

The preset voltage thresholds are accurate to ±1.5% over

temperature. The LTC2938 and LTC2939 also feature ad-

justable inputs with a 0.5V nominal threshold.

The reset and watchdog timeout periods 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

a weak internal pull-up and may be externally pulled up

to a user-defined voltage.

The 80μA supply current makes the LTC2938 and LTC2939

ideal for power conscious systems. The LTC2939 moni-

tors up to six supplies and the LTC2938 monitors up to

four supplies.

6-Supply Monitor 12V (ADJ), 5V, 3.3V, 2.5V, 1.8V, 1.2V (ADJ)

FEATURES

APPLICATIONS

n

Simultaneously Monitors Four (LTC2938) or Six

Supplies (LTC2939)

n

Sixteen User-Selectable Combinations of 5V, 3.3V,

2.5V, 1.8V, 1.5V, 1.2V and/or ± Adjustable Voltage

Thresholds

n

Guaranteed Threshold Accuracy: ±1.5%

n

Adjustable Reset and Watchdog Timeout

n

Low Supply Current: 80μA Typical

n

Power Supply Glitch Immunity

n

n

High Temperature Operation to 125°C

n

12-Pin 4mm

× 3mm DFN or 12-Lead MSOP

(LTC2938) and 16-Lead MSOP Package (LTC2939)

n

Desktop and Notebook Computers

n

Multivoltage Systems

n

Telecom Equipment

n

Network Servers

n

Automotive Control Systems

Voltage Configuration Table

LTC2939

1.2V

1.8V

2.5V

3.3V

5V

12V

293839 TA01

47nF

47nF

RST

WDO

WDI

GND

CWT

CRT

V1

V2

V3

V4

V5

V6

SYSTEM

LOGIC

R1

59k

1%

100k

1%

100k

1%

124k

1%

2150k

1%

R2

40.2k

1%

0.1μF

0.1μF

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 6967591, 7239251, 7119714.