LTC2904/LTC2905
1
29045fd
TYPICAL APPLICATION
DESCRIPTION
Precision Dual Supply
Monitors with Pin-Selectable
Thresholds
The LTC
®
2904/LTC2905 are dual supply monitors in-
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 exter-
nal 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.
5V, 3.3V Dual Supply Monitor with 5% Tolerance
FEATURES
APPLICATIONS
n
Monitors Two Inputs Simultaneously
n
Nine Threshold Combinations
n
Three Supply Tolerances (5%, 7.5%, 10%)
n
Guaranteed Threshold Accuracy: ±1.5% of
Monitored Voltage Over Temperature
n
Internal V
CC
Auto Select
n
Power Supply Glitch Immunity
n
200ms Reset Time Delay (LTC2904 Only)
n
Adjustable Reset Time Delay (LTC2905 Only)
n
Open Drain RST Output
n
Guaranteed RST for V1 ≥ 1V or V2 ≥ 1V
n
Low Profi le (1mm) SOT-23 (ThinSOT™) and
Plastic (3mm × 2mm) DFN Packages
n
Desktop and Notebook Computers
n
Handheld Devices
n
Network Servers
n
Core, I/O Monitor
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
V1
S1
S2
TOL
V2
TMR
GND
RST
LTC2905
22nF
0.1μF0.1μF
DC/DC
CONVERTER
SYSTEM
LOGIC
29045 TA01
3.3V
5V
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
