LTC2904/LTC2905

1

sn29045 29045fs

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

■

Nine Threshold Combinations

Monitored Voltage Over Temperature

■

200ms Reset Time Delay (LTC2904 Only)

■

Guaranteed RST for V1 ≥ 1V or V2 ≥ 1V

(3mm x 2mm) DFN Packages

■

Handheld Devices

Precision Dual Supply Monitors

with Pin-Selectable Thresholds

The LTC

tended for systems with two supply voltages. The dual

supply monitors have a common reset output with delay

(200ms for the LTC2904 and adjustable using an external

capacitor for the LTC2905). This product provides a

precise, space-conscious and micropower solution for

supply monitoring.

The LTC2904/LTC2905 feature a tight 1.5% threshold

accuracy over the whole operating temperature range,

and glitch immunity to ensure reliable reset operation

without false triggering. The open drain RST output is

guaranteed to be in the correct state for inputs down to 1V.

The LTC2904/LTC2905 also feature three programming

input pins, which program the threshold and tolerance

level without requiring any external components. These

three programming pins provide a total of 27 different

voltage level and tolerance combinations, eliminating

the need to have different parts for development and

implementation of different systems with different voltage

levels requiring monitoring function.

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

V1

S1

S2

TOL

V2

TMR

GND

RST

LTC2905

22nF

0.1µF

0.1µF

DC/DC

CONVERTER

SYSTEM

LOGIC

29045 TA01

3.3V

5V

5V, 3.3V Dual Supply Monitor with 5% Tolerance

Table 1. Voltage Threshold Programming

V1

V2

S1

S2

5.0

3.3

V1

V1

3.3

2.5

Open

GND

3.3

1.8

V1

Open

3.3

1.5

Open

V1

3.3

1.2

Open

Open

2.5

1.8

GND

GND

2.5

1.5

GND

Open

2.5

1.2

GND

V1

2.5

1.0

V1

GND

APPLICATIO S

ThinSOT is a trademark of Linear Technology Corporation.