A/D, D/C Converters for Image Signal Processing MN655431SH Low Power 8-Bit CMOS A/D Converter for Image Processing Overview The MN655431SH is an 8-bit CMOS analog-to-digital converter with a maximum conversion rate of 15 MSPS. It uses a half flash structure based on chopper comparators and achieves both high speed and low power consumption with multiplex processing. It provides separate power supply pins for the circuits driving the low-voltage digital output pins. Features Maximum conversion rate: 15 MSPS (min.) Linearity error: ±0.5 LSB (typ.) Differential linearity error: ±0.4 LSB (typ.) Power supply voltage: 4.40 to 5.25 V Power consumption: 90 mW (typ.) Pin Assignment DVDDL DVSS (LSB) D0 D1 D2 D3 D4 D5 D6 (MSB) D7 DVDD CLK 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 DVSS VRB VRBS AVSS AVSS VIN AVDD VRT VRTS AVDD AVDD DVDD Applications Digital television receivers (TOP VIEW) Digital video equipment Digital image processing equipment SSOP024-P-0300 1 MN655431SH A/D, D/C Converters for Image Signal Processing Lower comparator (4 bits) 13 DVDD AVDD 14 AVDD 15 VRTS 16 AVDD VIN VRT 17 18 19 AVSS 20 VRBS AVSS 21 VRB 22 23 24 DVSS Block Diagram Lower comparator (4 bits) Reference resistor Encoder (4 bits) Encoder (4 bits) Lower comparator (4 bits) Clock generator Data latch 2 12 CLK 11 DVDD 10 D7(MSB) 9 D6 8 D5 D4 7 6 D3 5 D2 D1 4 3 D0(LSB) DVSS DVDDL 1 2 Encoder (4 bits) A/D, D/C Converters for Image Signal Processing MN655431SH Pin Descriptions Pin No. 1 Symbol DVDDL 2 DVSS 3 D0 Digital output (LSB) 4 D1 Digital output 5 D2 Digital output 6 D3 Digital output 7 D4 Digital output 8 D5 Digital output 9 D6 Digital output 10 D7 11 DVDD Function Description Power supply for digital output circuits Ground for digital circuits Digital output (MSB) Power supply for digital circuits 12 CLK Sampling clock 13 DVDD Power supply for digital circuits 14 AVDD Power supply for analog circuits 15 AVDD Power supply for analog circuits 16 VRTS Power supply for reference voltage (TOP) 17 VRT Reference voltage (TOP) 18 AVDD 19 VIN 20 AVSS Ground for analog circuits 21 AVSS Ground for analog circuits 22 VRBS Power supply for reference voltage (BOTTOM) 23 VRB Reference voltage (BOTTOM) 24 DVSS Ground for digital circuits Power supply for analog circuits Analog input Absolute Maximum Ratings Ta=25˚C Parameter Power supply voltage Symbol VDD Rating – 0.3 to +7.0 Unit V Power supply voltage for digital outputs DVDDL – 0.3 to +VDD +0.3 V VI AVSS – 0.3 to VDD +0.3 V Output voltage VO DVSS – 0.3 to VDD +0.3 V Operating ambient temperature Topr –20 to +70 ˚C Storage temperature Tstg –55 to +125 ˚C Input voltage 3 MN655431SH A/D, D/C Converters for Image Signal Processing Recommended Operating Conditions VDD=AVDD=DVDD=5.0V, DVDDL=3.5V, VSS=AVSS=DVSS=0V, Ta=25˚C Parameter Power supply voltage Symbol VDD min 4.50 Power supply voltage for digital outputs DVDDL VIH Digital input "H" level typ 5.00 max 5.25 Unit V 3.4 3.6 V 2.4 VDD V voltage "L" level VIL VSS 0.8 V Reference voltage "H" level VRT 3.3 VDD V "L" level VRB VSS 1.5 "H" level pulse width tWH 30 Clock "L" level pulse width Analog input voltage Electrical Characteristics Parameter Power supply voltage tWL 30 VAIN VSS ns VDD Symbol IDD Conditions fCLK = 15 MHz min RES typ max Unit 18 26 mA 8 bit Linearity error EL fCLK=15MHz ±0.5 ±1.3 LSB Differential linearity error ED VRT=3.5V ±0.4 ±0.7 LSB Maximum conversion rate Fc(max.) 15 fCLK 1 15 2 VRT –VRB V –2 mA Clock frequency 4 V VDD=AVDD=DVDD=5.0V, DVDDL=3.5V, AVSS=DVSS=0V, Ta=25˚C (includes reference power supply) Resolution V ns VRB=1.5V Analog input dynamic range DR Output "H" level IOH VOH=DVDDL – 0.8V current "L" level IOL VOL= 0.4V MSPS 2 MHz mA Output delay time td 30 Analog input capacitance CI 18 45 ns pF A/D, D/C Converters for Image Signal Processing MN655431SH Timing Chart The chip samples the analog input at the falling edge of the clock signal and provides the corresponding digital output 2.5 clock cycles later at the rising edge of the clock signal. tWH tWL Clock Analog input Data output N N–3 N+1 N–2 N+2 N+3 N–1 N N+4 N+1 td(30ns) Note: The circles indicate analog signal sampling points. 5 MN655431SH A/D, D/C Converters for Image Signal Processing Package Dimensions (Unit:mm) SSOP024-P-0300 6.5±0.2 24 13 +0.10 0.15 -0.05 7.5±0.2 5.5±0.2 1.0±0.2 (0.5) 0.5 0.2±0.1 1.6±0.3 12 0.1±0.1 1 1.5±0.2 0 to 10° SEATING PLANE 6 0.5±0.2