1FEATURES
2• Built-In Track-and-Hold Function
• No Missing Codes
• No External Clocking
• Single Supply—5 VDC
• Easy Interface to All Microprocessors, or
Operates Stand-Alone
• Latched TRI-STATE Output
• Logic Inputs and Outputs Meet Both MOS and
T2L 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 in. Standard Width 20-Pin PDIP
• 20-Pin PLCC
• 20-Pin SOIC

KEY SPECIFICATIONS
• Resolution: 8 Bits
• Conversion Time
– 2.5 μs Max (RD Mode)
– 1.5 μs Max (WR-RD Mode)
• Low Power: 75 mW Max
• Total Unadjusted Error: ±½ LSB and ± 1 LSB

DESCRIPTION
By using a half-flash conversion technique, the 8-bit
ADC0820-N 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-N 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-N has been designed to appear as a
memory location or I/O port without the need for
external interfacing logic.