LTC2905_15 Datasheet, PDF (1/16 Pages) Linear Technology – Precision Dual Supply Monitors with Pin-Selectable Thresholds

LTC2904/LTC2905
FEATURES
Precision Dual Supply
Monitors with Pin-Selectable
Thresholds
DESCRIPTION
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 VCC 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 Profile (1mm) SOT-23 (ThinSOT™) and}
Plastic (3mm × 2mm) DFN Packages
APPLICATIONS
n _{Desktop and Notebook Computers}
n _{Handheld Devices}
n _{Network Servers}
n _{Core, I/O Monitor}
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.
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.
TYPICAL APPLICATION
5V, 3.3V Dual Supply Monitor with 5% Tolerance
5V
DC/DC
SYSTEM
CONVERTER
3.3V
LOGIC
0.1μF
V1
V2
LTC2905
S1
TMR
S2
GND
TOL
RST
0.1μF
22nF
29045 TA01
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
29045fd
1