Rainbow Electronics ADC0820 User Manual
General description, Key specifications, Features
TL H 5501
ADC0820
8-Bit
High
Speed
m
P
Compatible
AD
Converter
with
TrackHold
Function
February 1995
ADC0820 8-Bit High Speed mP Compatible
A D Converter with Track Hold Function
General Description
By using a half-flash conversion technique
the 8-bit
ADC0820 CMOS A D offers a 1 5 ms conversion time and
dissipates only 75 mW of power The half-flash technique
consists of 32 comparators a most significant 4-bit ADC
and a least significant 4-bit ADC
The input to the ADC0820 is tracked and held by the input
sampling circuitry eliminating the need for an external sam-
ple-and-hold for signals moving at less than 100 mV ms
For ease of interface to microprocessors the ADC0820 has
been designed to appear as a memory location or I O port
without the need for external interfacing logic
Key Specifications
Y
Resolution
8 Bits
Y
Conversion Time
2 5 ms Max (RD Mode)
1 5 ms Max (WR-RD Mode)
Y
Input signals with slew rate of 100 mV ms converted
without external sample-and-hold to 8 bits
Y
Low Power
75 mW Max
Y
Total Unadjusted Error
g
LSB and
g
1 LSB
Features
Y
Built-in track-and-hold function
Y
No missing codes
Y
No external clocking
Y
Single supply
5 V
DC
Y
Easy interface to all microprocessors
or operates
stand-alone
Y
Latched TRI-STATE
output
Y
Logic inputs and outputs meet both MOS and T
2
L volt-
age level specifications
Y
Operates ratiometrically or with any reference value
equal to or less than V
CC
Y
0V to 5V analog input voltage range with single 5V
supply
Y
No zero or full-scale adjust required
Y
Overflow output available for cascading
Y
0 3
standard width 20-pin DIP
Y
20-pin molded chip carrier package
Y
20-pin small outline package
Y
20-pin shrink small outline package (SSOP)
Connection and Functional Diagrams
Dual-In-Line Small Outline and
SSOP Packages
TL H 5501 – 1
Top View
Molded Chip Carrier
Package
TL H 5501 – 33
TL H 5501 – 2
FIGURE 1
See Ordering Information
TRI-STATE
is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation
RRD-B30M115 Printed in U S A