AD7824

`4- or 8-Analog Input Channels
`Built-In Track/Hold Function
`10 kHz Signal Handling on Each Channel
`Fast Microprocessor Interface
`Single 5 V Supply
`Low Power: 50 mW
`Fast Conversion Rate, 2.5 s/Channel
`Tight Error Specification: 1/2 LSB

V_DD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V, 7 V
Digital Input Voltage to GND
         (RD, CS, A0, A1 & A2) . . . . . . . . .  0.3 V, V_DD + 0.3 V
Digital Output Voltage to GND
        (DB₀, DB7, RDY & INT) . . . . . . . . . .0.3 V, V_DD + 0.3 V
V_REF (+) to GND . . . . . . . . . . . . . . . . . V_REF (), V_DD + 0.3 V
V_REF () to GND . . . . . . . . . . . . . . . . . . . . . . . . 0 V, V_REF (+)
Analog Input (Any Channel) . . . . . . . . . 0.3 V, V_DD + 0.3 V
Operating Temperature Range
        Commercial (K, L Versions) . . . . . . . . . . . 0°C to 70°C
        Industrial (B, C Versions) . . . . . . .  . 25°C to +85°C
        Extended (T, U Versions) . . . . . . . . 55°C to +125°C
Storage Temperature Range . . . . . . . . . 65°C to +150°C
Lead Temperature (Soldering, 10 secs) . . . . .  . . . . . .300°C
Power Dissipation (Any Package) to 75°C . . . .  . . .  450 mW
Derates above 75°C by . . . . . . . . . . . . . . . . . . . . . 6 mW/°C

The AD7824 and AD7828 are high-speed, multichannel, 8-bit ADCs with a choice of 4 (AD7824) or 8 (AD7828) multiplexed analog inputs. A half-flash conversion technique gives a fast conversion rate of 2.5 s per channel and the parts have a builtin track/hold function capable of digitizing full-scale signals of 10 kHz (157 mV/s slew rate) on all channels. The AD7824 and AD7828 operate from a single 5 V supply and have an analog input range of 0 V to 5 V, using an external 5 V reference.

Microprocessor interfacing of the parts is simple, using standard Chip Select (CS) and Read (RD) signals to initiate the conversion and read the data from the three-state data outputs. The half-flash conversion technique means that there is no need to generate a clock signal for the ADC. The AD7824 and AD7828 can be interfaced easily to most popular microprocessors.

The AD7824 and AD7828 are fabricated in an advanced, all ion-implanted, linear-compatible CMOS process (LC2MOS) and have low power dissipation of 40 mW (typ). The AD7824 is available in a 0.3" wide, 24-lead "skinny" DIP, while the AD7828 is available in a 0.6" wide, 28-lead DIP and in 28- terminal surface mount packages.