LTC2938 LINER [Linear Technology], LTC2938 Datasheet - Page 6

• Manufacturer Part Number: LTC2938
• Description: Confi gurable 4- and 6-Supply Monitors with Watchdog Timer
• Manufacturer: LINER [Linear Technology]

LTC2938/LTC2939
TYPICAL PERFORMANCE CHARACTERISTICS
PIN FUNCTIONS
CRT: Reset Timeout Capacitor. Attach an external capaci-
tor (C
capacitor generates a 94ms reset delay time. Leaving CRT
unconnected generates a minimum timeout period of ap-
proximately 20μs which will vary depending on parasitic
capacitance on the pin.
6
15
12
9
6
3
0
RT
0
I
T
SINK
A
) to GND to set a reset timeout of 2ms/nF . A 47nF
= 25°C
vs Supply Voltage (RST)
1
V1 OR V2 (V)
2
V
18
15
12
OL
9
6
3
0
1
= 0.4V
WDO Pull-Up Current vs V2
T
WDO = GND
A
= 25°C
3
V
OL
= 0.2V
2
4
29389 G13
V2 (V)
3
5
500
400
200
100
300
4
0
0
29389 G16
Voltage Output Low
vs Sink Current (RST, WDO)
V1 = 5V
V2 = 3V
5
2
25°C
4
I
SINK
CWT: Watchdog Timeout Capacitor. Attach a capacitor (C
between CWT and GND to set a watchdog timeout period
of 20ms/nF . A 47nF capacitor generates a 940ms watchdog
timeout period. Leaving CWT unconnected generates a
minimum timeout period of approximately 200μs which
85°C
(mA)
6
–40°C
1.50
1.25
1.00
0.75
0.50
–50
8
WDI Input Threshold
vs Temperature
125°C
29389 G14
–25
10
0
TEMPERATURE (°C)
OPEN (MAXIMUM)
OPEN (MINIMUM)
25
–10
–15
–20
HIGH
20
15
10
–5
5
0
–50
WDI Input Current vs Temperature
50
–25
75
0
100
TEMPERATURE (°C)
V
LOW
V
WDI
29389 G17
WDI
25
= 1.1V
125
= 5V
50
V
V
WDI
WDI
75
= 0V
= 0.7V
100
29389 G15
293839ff
WT
125
)