Datasheet

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SLUS247F − APRIL 1997 − REVISED NOVEMBER 2007
2
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ORDERING INFORMATION
T
A
PACKAGED DEVICES
(3)
T
A
(D) (N) (PW)
−40°C to 95°C UCC2946D UCC2946N UCC2946PW
0°C to 70°C UCC3946D UCC3946N UCC3946PW
(1)
The D and PW packages are also available taped and reeled. Add an R suffix to the device type (i.e., UCC2946DR) for quantities of 3,000
devices per reel.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted
(1)
UCC2946
UCC3946
UNIT
Input voltage range, V
IN
10 V
Junction temperature range, T
J
−55 to 150
Storage temperature, T
stg
−65 to 150
°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 300
C
(1)
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is
not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Voltages are with respect to
GND. Currents are positive into, and negative out of the specified terminal.
1
2
3
4
8
7
6
5
GND
RTH
RES
RP
VDD
WDI
WP
WDO
D PACKAGE
(TOP VIEW)
TERMINAL FUNCTIONS
TERMINAL
I/O
DESCRIPTION
NAME NO.
I/O
DESCRIPTION
GND 1 − Ground reference for the device
RES 3 O
This pin is high only if the voltage on the RTH has risen above 1.235 V. Once RTH rises above the threshold, this
pin remains low for the reset period. This pin asserts low and remains low if the RTH voltage dips below 1.235 V for
an amount of time determined by Figure 1.
RTH 2 I
This input compares its voltage to an internal 1.25-V reference. By using external resistors, a user can program any
desired reset threshold.
RP 4 I This pin allows the user to program the reset period by adjusting an external capacitor.
VDD 8 I Supply voltage for the device.
WDI 7 I
This pin is the input to the watchdog timer. If this pin is not toggled or strobed within the watchdog period, WDO is
asserted.
WDO 5 O
This pin is the watchdog output. This pin is asserted low if the WDI pin is not strobed or toggled within the watchdog
period.
WP 6 I This pin allows the user to program the watchdog period by adjusting an external capacitor.