ADC0808CCV/NOPB

FEATURES
2 Easy Interface to All Microprocessors Operates Ratiometrically or with 5 VDC or

Analog Span Adjusted Voltage Reference No Zero or Full-Scale Adjust Required 8-Channel Multiplexer with Address Logic 0V to VCC Input Range Outputs meet TTL Voltage Level Specifications ADC0808 Equivalent MM74C949 ADC0809 Equivalent to MM74C949-1

Resolution: 8 Bits Total Unadjusted Error: LSB and ±1 LSB Single Supply: 5 VDC Low Power: 15 mW Conversion Time: 100 s

DESCRIPTION

The ADC0808, ADC0809 data acquisition component is a monolithic CMOS device with an 8-bit analog-todigital converter, 8-channel multiplexer and microprocessor compatible control logic. The 8-bit A/D converter uses successive approximation as the conversion technique. The converter features a high impedance chopper stabilized comparator, a 256R voltage divider with analog switch tree and a successive approximation register. The 8-channel multiplexer can directly access any of 8-single-ended analog signals.

The device eliminates the need for external zero and full-scale adjustments. Easy interfacing to microprocessors is provided by the latched and decoded multiplexer address inputs and latched TTL TRI-STATE outputs.

The design of the ADC0808, ADC0809 has been optimized by incorporating the most desirable aspects of several A/D conversion techniques. The ADC0808, ADC0809 offers high speed, high accuracy, minimal temperature dependence, excellent long-term accuracy and repeatability, and consumes minimal power. These features make this device ideally suited to applications from process and machine control to consumer and automotive applications. For 16channel multiplexer with common output (sample/hold port) see ADC0816 data sheet. (See AN-247 (Literature Number SNOA595) for more information.)

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.

Supply Voltage (VCC)(4) Voltage at Any Pin Except Control Inputs
Package Dissipation at TA=25°C Lead Temp. (Soldering, 10 seconds)

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating the device beyond its specified operating conditions.

(2) All voltages are measured with respect to GND, unless otherwise specified. (3) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications. (4) A Zener diode exists, internally, from VCC to GND and has a typical breakdown voltage of 7 VDC. (5) Human body model, 100 pF discharged through 1.5 k resistor.

(2) All voltages are measured with respect to GND, unless otherwise specified.

Converter Specifications: VCC=5 VDC=VREF+, VREF(-)=GND, TMINTATMAX and fCLK=640 kHz unless otherwise stated.

(1) Total unadjusted error includes offset, full-scale, linearity, and multiplexer errors. See Figure 5. None of these A/Ds requires a zero or full-scale adjust. However, if an all zero code is desired for an analog input other than if a narrow full-scale span exists (for example: to 4.5V full-scale) the reference voltages can be adjusted to achieve this. See Figure 15.

Input Resistance Analog Input Voltage Range Voltage, Top of Ladder
to 70°C TMIN to TMAX From Ref(+) to Ref(-) See (2) V(+) or V(-) Measured at Ref(+)
Voltage, Bottom of Ladder Comparator Input Current

(2) Two on-chip diodes are tied to each analog input which will forward conduct for analog input voltages one diode drop below ground or

one diode drop greater than the VCCn supply. The spec allows 100 mV forward bias of either diode. This means that as long as the analog VIN does not exceed the supply voltage by more than 100 mV, the output code will be correct. To achieve an absolute to 5VDC input voltage range will therefore require a minimum supply voltage of 4.900 VDC over temperature variations, initial tolerance and loading.

(3) Comparator input current is a bias current into or out of the chopper stabilized comparator. The bias current varies directly with clock

frequency and has little temperature dependence (Figure 8). See ANALOG COMPARATOR INPUTS

Digital Levels and DC Specifications: ADC0808CCV, ADC0809CCN and 4.75VCC5.25V, -40°CTA+85°C unless otherwise noted

Logical "1" Input Current (The Control Inputs)
Logical "0" Input Current (The Control Inputs)
Timing Specifications VCC=VREF(+)=5V, VREF(-)=GND, tr=tf=20 ns and TA=25°C unless otherwise noted.