Datasheet

LTC2932
10
2932fb
APPLICATIONS INFORMATION
At power-up, once V1 or V2 reaches 2.4V, the monitor
enters a setup period of approximately 150μs. During the
setup time, the voltage on the VPG pin is sampled and the
monitor is confi gured to the desired input combination. The
comparators are enabled and supply monitoring begins.
Do not add capacitance to the VPG pin.
The two supply tolerance inputs, T0 and T1, confi gure the
global supply tolerance. Larger tolerances provide more
headroom by lowering the trip thresholds. Table 2 lists the
input combinations for each of the tolerance modes.
Figure 3. Setting the Positive Adjustable Trip Point
+
–
0.5V
5% TOLERANCE MODE
2932 F03
V3, V4, V5 OR V6
V
TRIP
R3
1%
R4
1%
LTC2932
2932 F04
V4
VREF
V
TRIP
R4
1%
R3
1%
LTC2932
Figure 4. Setting the Negative Adjustable Trip Point
V
SUPPLY
(V) V
TRIP
(V) R3 (kΩ) R4 (kΩ)
12 11.25 2150 100
10 9.4 1780 100
8 7.5 1400 100
7.5 7 1300 100
6 5.6 1020 100
5 4.725 845 100
3.3 3.055 511 100
3 2.82 464 100
2.5 2.325 365 100
1.8 1.685 237 100
1.5 1.410 182 100
1.2 1.120 124 100
1 0.933 86.6 100
0.9 0.840 68.1 100
*See Figure 3.
Table 3. Suggested 1% Resistor Values for the ADJ Inputs
V
SUPPLY
(V) V
TRIP
(V) R3 (kΩ) R4 (kΩ)
–2 –1.87 187 121
–5 –4.64 464 121
–5.2 –4.87 487 121
–10 –9.31 931 121
–12 –11.30 1130 121
*See Figure 4.
Table 4. Suggested 1% Resistor Values for the –ADJ Inputs
T0 T1 TOLERANCE (%) V
REF
(V)
Low Low 5 1.210
Low High 7.5 1.178
High Low 10 1.146
High High 12.5 1.113
Table 2. Tolerance Selection
Table 1. Voltage Threshold Modes*
MODE V1 (V) V2 (V) V3 (V) V4 (V) R1 (kΩ) R2 (kΩ)
V
PG
V
REF
0 5 3.3 ADJ ADJ Open Short 0.000
1 5 3.3 ADJ –ADJ 93.1 9.53 0.094
2 3.3 2.5 ADJ ADJ 86.6 16.2 0.156
3 3.3 2.5 ADJ –ADJ 78.7 22.1 0.219
4 3.3 2.5 1.5 ADJ 71.5 28 0.281
5 5 3.3 2.5 ADJ 66.5 34.8 0.344
6 5 3.3 2.5 1.8 59 40.2 0.406
7 5 3.3 2.5 1.5 53.6 47.5 0.469
8 5 3 2.5 ADJ 47.5 53.6 0.531
9 5 3 ADJ ADJ 40.2 59 0.594
10 3.3 2.5 1.8 1.5 34.8 66.5 0.656
11 3.3 2.5 1.8 ADJ 28 71.5 0.719
12 3.3 2.5 1.8 –ADJ 22.1 78.7 0.781
13 5 3.3 1.8 –ADJ 16.2 86.6 0.844
14 5 3.3 1.8 ADJ 9.53 93.1 0.906
15 5 3 1.8 ADJ Short Open 1
*V5 and V6 are always adjustable (ADJ).