HI-8437_16 Datasheet, PDF (1/21 Pages) Holt Integrated Circuits – 32-Channel High Impedance Low Threshold Sensor with SPI Interface

January 2016
HI-8437
32-Channel High Impedance
Low Threshold Sensor with SPI Interface
GENERAL DESCRIPTION
The HI-8437 is a 32-channel high impedance discrete-to-
digital sensor fabricated with Silicon-on-Insulator (SOI)
technology designed to interface with a Serial Peripheral
Interface (SPI).
The four banks of 8 sense inputs can be programmed to
detect one of two threshold ranges, VTHR1, VTHR2.
All sense inputs have a 400KΩ resistor to ground and are
internally lightning protected to DO160G, Section 22, Cat
AZ, BZ and ZZ without external components.
The sensing circuit window comparator thresholds are set
by programming the center threshold and hysteresis
registers to values from 0.4V to 5.2V. The digital values of
the sensed inputs can be read either one bank at a time or
all 4 banks with one command.
Interface to the digital subsystem is simple CMOS logic
inputs and outputs. The logic pins are compatible with 3.3V
logic allowing direct connection to a wide range of
microcontrollers or FPGAs.
FEATURES
· Robust CMOS Silicon-on-Insulator (SOI) technology
· 32-channel Programmable Sense Operation, two
programmable threshold ranges, 4 X 8 Input Sensors
· Programmable HI/LO Threshold and Hysteresis in
0.1V steps, from 0.4V to 5.2V.
· Single Low Voltage Supply Operation
· Logic Operation from 3.0V to 3.6V
· 20 MHz Serial Peripheral Interface (SPI)
· Lightning Protected Sense Inputs
· Internal Self-Test
PIN CONFIGURATIONS
NC - 1
SENSE_0 - 2
SENSE_1 - 3
SENSE_2 - 4
SENSE_3 - 5
SENSE_4 - 6
SENSE_5 - 7
SENSE_6 - 8
SENSE_7 - 9
SENSE_8-10
SENSE_9-11
HI-8437PQI
HI-8437PQT
HI-8437PQM
33 - SENSE_27
32 - NC
31 - SENSE_26
30 - SENSE_25
29 - SENSE_24
28 - SENSE_23
27 - SENSE_22
26 - SENSE_21
25 - SENSE_20
24 - SENSE_19
23 - SENSE_18
44 Pin Plastic Quad Flat Pack (PQFP)
10mm x 10mm
NC - 1
SENSE_0 - 2
SENSE_1 - 3
SENSE_2 - 4
SENSE_3 - 5
SENSE_4 - 6
SENSE_5 - 7
SENSE_6 - 8
SENSE_7 - 9
SENSE_8 -10
SENSE_9 -11
HI-8437PCI
HI-8437PCT
HI-8437PCM
33 - SENSE_27
32 - NC
31 - SENSE_26
30 - SENSE_25
29 - SENSE_24
28 - SENSE_23
27 - SENSE_22
26 - SENSE_21
25 - SENSE_20
24 - SENSE_19
23 - SENSE_18
APPLICATION
· Avionics Discrete to Digital Sensing
· Low thresholds applications.
44 Pin Plastic QFN
7mm x 7mm
(DS8437 Rev. A)
HOLT INTEGRATED CIRCUITS
www.holtic.com
01/16