ADC0820 8-Bit High Speed µP Compatible A/D Converter with Track/Hold Function
June 1999
ADC0820
8-Bit High Speed µP 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 µs 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
sample-and-hold for signals moving at less than 100 mV/µs.
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.
Features
n
n
n
n
n
n
n
n
n
8 Bits
2.5 µs Max (RD Mode)
n
n
n
n
n
n
Built-in track-and-hold function
No missing codes
No external clocking
Single supply — 5 V
DC
Easy interface to all microprocessors, or operates
stand-alone
Latched TRI-STATE
®
output
Logic inputs and outputs meet both MOS and T
2
L
voltage level specifications
Operates ratiometrically or with any reference value
equal to or less than V
CC
0V to 5V analog input voltage range with single 5V
supply
No zero or full-scale adjust required
Overflow output available for cascading
0.3" standard width 20-pin DIP
20-pin molded chip carrier package
20-pin small outline package
20-pin shrink small outline package (SSOP)
Key Specifications
n
Resolution
n
Conversion Time
n
Low Power
n
Total Unadjusted
Error
1.5 µs Max (WR-RD Mode)
75 mW Max
±
1
⁄
2
LSB and
±
1 LSB
Connection and Functional Diagrams
Dual-In-Line, Small Outline
and SSOP Packages
Molded Chip Carrier
Package
DS005501-1
DS005501-33
Top View
TRI-STATE
®
is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS005501
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
