MAX191 19-4506 Rev 4 2/97 Low-Power, 12-Bit Sampling ADC with Internal Reference and Power-Down General Description Features 12-Bit Resolution, 1/2LSB Linearity The MAX191 is a monolithic, CMOS, 12-bit analog-to- digital converter (ADC) featuring differential inputs, +5V or 5V Operation track/hold (T/H), internal voltage reference, internal or Built-In Track/Hold external clock, and parallel or serial P interface. The Internal Reference with Adjustment Capability MAX191 has a 7.5s conversion time, a 2s acquisition Low Power: 3mA Operating Mode time, and a guaranteed 100ksps sample rate. 20A Power-Down Mode The MAX191 operates from a single +5V supply or from 100ksps Tested Sampling Rate dual 5V supplies, allowing ground-referenced bipolar Serial and 8-Bit Parallel P Interface input signals. The device features a logic power-down input, which reduces the 3mA V supply current to 24-Pin Narrow DIP and Wide SO Packages DD 50A max, including the internal-reference current. Ordering Information Decoupling capacitors are the only external compo- nents needed for the power supply and reference. This ERROR PART TEMP. RANGE PIN-PACKAGE (LSB) ADC operates with either an external reference, or an internal reference that features an adjustment input for MAX191ACNG 0C to +70C 24 Narrow Plastic DIP 1/2 trimming system gain errors. MAX191BCNG 0C to +70C 24 Narrow Plastic DIP 1 The MAX191 provides three interface modes: two 8-bit MAX191ACWG 0C to +70C 24 Wide SO 1/2 parallel modes, and a serial interface mode that is com- MAX191BCWG 0C to +70C 24 Wide SO 1 TM TM TM patible with SPI , QSPI , and MICROWIRE serial- MAX191BC/D 0C to +70C Dice* 1 interface standards. MAX191AENG -40C to +85C 24 Narrow Plastic DIP 1/2 MAX191BENG -40C to +85C 24 Narrow Plastic DIP 1 Applications MAX191AEWG -40C to +85C 24 Wide SO 1/2 Battery-Powered Data Logging MAX191BEWG -40C to +85C 24 Wide SO 1 PC Pen Digitizers MAX191AMRG -55C to +125C 24 Narrow CERDIP** 1/2 High-Accuracy Process Control MAX191BMRG -55C to +125C 24 Narrow CERDIP** 1 Electromechanical Systems Data-Acquisition Boards for PCs * Dice are specified at T = +25C, DC parameters only. A ** Contact factory for availability and processing to MIL-STD-883. Automatic Testing Systems Telecommunications Pin Configuration Digital Signal Processing (DSP) TOP VIEW Functional Diagram PD V 1 DD 24 V CLK/SCLK DD V CLK/SCLK SS 2 23 24 23 5 18 AIN+ PAR VREF D7/DOUT 3 22 OSC 6 3-STATE 17 REFADJ D6/SCLK OUT AIN- 4 HBEN OUTPUT 21 16 D5/SSTRB 15 MAX191 VREF CS 5 20 D4 8-BIT 14 BUS D3/D11 REFADJ 6 RD 2.46V 19 13 AND D2/D10 REF 11 AGND SERIAL D7/DOUT 7 18 12 D1/D9 I/O 10 D0/D8 BIP 8 17 D6/SCLK OUT 3 AIN + BUSY D5/SSTRB 9 16 4 AIN - 20 CS D0/D8 D4 10 15 IN REF OUT 19 CONTROL RD 12-BIT 9 D1/D9 LOGIC BUSY 14 D3/D11 MAX191 11 SAR ADC 21 HBEN DGND D2/D10 12 13 1 712 2 22 8 V PD BIP SS PAR AGND DGND DIP/SO SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. Maxim Integrated Products 1 For free samples & the latest literature: Low-Power, 12-Bit Sampling ADC with Internal Reference and Power-Down ABSOLUTE MAXIMUM RATINGS V to DGND............................................................-0.3V to +7V Operating Temperature Ranges DD V to AGND ............................................................-7V to +0.3V MAX191 C ................................................................0C to +70C SS V to V ..............................................................................12V MAX191 E .............................................................-40C to +85C DD SS AGND, VREF, REFADJ to DGND................-0.3V to (V + 0.3V) MAX191 M ..........................................................-55C to +125C DD AIN+, AIN-, PD to V .................................-0.3V to (V + 0.3V) Storage Temperature Range.....................................-65C to +160C SS DD CS, RD, CLK, BIP, HBEN, PAR, to DGND....-0.3V to (V + 0.3V) Lead Temperature (soldering, 10sec).....................................+300C DD BUSY, D0D7 to DGND..............................-0.3V to (V + 0.3V) DD Continuous Power Dissipation (T = +70C) A Narrow Plastic DIP (derate 13.33mW/C above +70C)....1067mW Wide SO (derate 11.76mW/C above +70C) ......................941mW Narrow CERDIP (derate 12.50mW/C above +70C) ........1000mW Stresses beyond those listed under Absolute Maximum Rating may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 5V 5%, V = 0V or -5V 5%, f = 1.6MHz, 50% duty cycle, AIN- = AGND, BIP = 0V, slow-memory mode, internal-reference DD SS CLK mode, reference compensation modeexternal, synchronous operation, Figure 6, T = T to T , unless otherwise noted.) (Note 1) A MIN MAX PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 2) Resolution 12 Bits MAX191A 1/2 Integral Nonlinearity INL LSB MAX191B 1 Differential Nonlinearity DNL No missing codes over temperature 1 LSB MAX191A 1 Offset Error LSB MAX191B 2 MAX191A 2 Gain Error (Note 3) LSB MAX191B 3 Gain-Error Tempco (Note 4) Excludes internal-reference drift 0.2 ppm/C DYNAMIC ACCURACY (sample rate = 100kHz, V = 4Vp-p) IN Signal-to-Noise plus Distortion 1kHz input signal, T = +25C SINAD 70 dB A Ratio Total Harmonic Distortion 1kHz input signal, T = +25C THD -80 dB A (up to the 5th Harmonic) 1kHz input signal, T = +25C Spurious-Free Dynamic Range SFDR 80 dB A CONVERSION RATE Synchronous CLK (12 to 13 CLKs) 7.50 8.125 t Conversion Time (Note 5) s CONV Internal CLK, C = 120pF 6 12 18 L Track/Hold Acquisition Time 2 s Aperture Delay 25 ns Aperture Jitter 50 ps External Clock Frequency f 0.1 1.6 MHz CLK Range (Note 6) 2 MAX191