Datasheet
Voltage Regulator
>
I
C
L-MIN
L
1 mA
1 µF
Temperature Sensor
SN65HVS882
SLAS601 – MAY 2008 ........................................................................................................................................................................................................
www.ti.com
Table 2. Function Table
INPUTS
FUNCTION
LD CLK CE
L X X Parallel load
H X H No change
H ↑ L Shift
(1)
(1) Shift = content of each internal register shifts towards serial outputs.
Data at SIP is shifted into first register.
The on-chip linear voltage regulator provides a 5-V supply to the internal and external circuitry, such as digital
isolators, with an output drive capability of 50 mA and a typical current limit of 115 mA. The regulator accepts
input voltages from 30 V down to 10 V. Because the regulator output is intended to supply external digital isolator
circuits proper output voltage decoupling is required. For best results connect a 1- µ F and a 0.1- µ F ceramic
capacitor as close as possible to the 5VOP output. For longer traces between the SN65HVS882 and isolators of
the ISO72xx family use additional 0.1- µ F and 10-pF capacitors next to the isolator supply pins. Make sure,
however, that the total load capacitance does not exceed 4.7 µ F.
For good stability the voltage regulator requires a minimum load current, I
L-MIN
. Ensure that under any operating
condition the ratio of the minimum load current in mA to the total load capacitance in µ F is larger than 1:
An on-chip temperature sensor monitors the device temperature and signals a fault condition if the internal
temperature reaches 150 ° C. If the internal temperature exceeds this trip point, the TOK output switches to an
active low state. If the internal temperature continues to rise, passing a second trip point at 170 ° C, all device
outputs are put in a high-impedance state.
A special condition occurs, however, when the chip temperature exceeds the second temperature trip point due
to an output short. Then the output buffer becomes three-state, thus separating the buffer from the external
circuitry. An internal 100-k Ω pull-down resistor, connecting the TOK pin to ground, is used as a cooling down
resistor, which continues to provide a logic low level to the external circuitry.
12 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): SN65HVS882