MAX158

An a/d conversion technique which combines some of the speed advantages of flash conversion with the circuitry savings of successive approximation is termed half-flash. In an 8-bit, half-flash converter, two 4-bit flash a/d sections are combined. The upper flash a/d compares the input signal to the reference and generates the upper 4 data bits. This data goes to an internal DAC, whose output is subtracted from the analog input. Then, the difference can be measured by the second flash a/d, which provides the lower 4 data bits.

The MAX154/MAX158 are high-speed multi-channel analog-to-digital converters (ADCs). The MAX154 has four analog input channels while the MAX158 has eight channels. Conversion time for both devices is 2.5s. The MAX154/MAX158 also feature a 2.5V on-chip reference,
forming a complete high-speed data acquisition system.
Both converters include a built-in track/hold, eliminating the need for an external track/hold. The analog input range is 0V to +5V, although the ADC operates from a single +5V supply.
Microprocessor interfaces are simplified by the ADC's ability to appear as a memory location or I/O port without the need for external logic. The data outputs use latched, three-state buffer circuitry to allow direct connection to a microprocessor data bus or system input port.

Supply Voltage, VDD to GND.............................................0V, +10V
Voltage at Any Other Pins............................GND -0.3V, VDD +0.3V
Output Current (REF OUT)......................................................30mA
Power Dissipation (any package) to +75°C .......................450mW
     Derate above +25°C by .............................................6mW/°C
Operating Temperature Ranges
     MAX15_ _C_ _.....................................................0°C to +70°C
     MAX15_ _E_ _..................................................-40°C to +85°C
     MAX15_ _M_ _ ...............................................-55°C to +125°C
Storage Temperature Range ..............................-65°C to +160°C
Lead Temperature (soldering, 10sec) ................................+300°C