DS1482 Datasheet, PDF (2/7 Pages) Dallas Semiconductor – 1-Wire Level Shifter and Line Driver with Load Sensor

PIN
1
3
4
5
7
10
12
13
14
16
2, 6, 8, 9,
11, 15
NAME
V_CCQ
SPU
START
TXD
GND
I/O
RXD
DONE
PCTLZ
V_CC
N.C.
DS1482
FUNCTION
Operating voltage for all circuitry that connects to the controlling
microprocessor (TXD, RXD, START, SPU, DONE pins).
This line is used to control the external strong pullup function. When SPU is
low, the strong pullup (PCTLZ) is high. When SPU is high and TXD is low,
PCTLZ is low.
This line acts as an enable control for the DONE pin. If START is high, then
DONE reflects the filtered digital output of the current-sense comparator. If
START is low, then DONE is low.
When TXD is low, the I/O pin is pulled resistively to V_CC. When TXD is
high, the 1-Wire bus is pulled to GND (for write-0, write-1, read, and reset
low times).
Ground Reference for V_CCQ, V_CC, 1-Wire
1-Wire Data
This line returns the digital state of the 1-Wire bus, level-shifted to swing
between V_CCQ and GND.
This line is high only when the buffered, filtered digital output from the
current-sense comparator indicates that the downstream 1-Wire slave device
is no longer sinking high current. This signal is enabled if START is high.
Active-low control pin for an external low-on-resistance, high-current
supply. This signal typically controls the gate of a P-channel MOSFET. This
signal is low when SPU is high and TXD is low.
Operating voltage for all circuitry that connects to the 1-Wire environment
(I/O and PCTLZ pins).
Not Connected
Figure 1. Block Diagram
LEVEL-SHIFT BOUNDARY
V_CCQ
RXD
V_CC
R_PUP
I/O
TXD
GND
DONE
START
SPU
+
-
Vref
PCTLZ
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