EM19101 EM19101 8-BIT 5 8-BIT 5A/D MSPS A/D CONVERTER (CMOS) MSPS CONVERTER (CMOS) GENERAL DESCRIPTION EM19101 is a 8-bit CMOS A/D converter for scanner use. The adoption of a 2-step parallel system achieves low consumption at a maximum conversion speed of 7 MSPS. FEATURES • • • • • • • 7MSPS maximum conversion speed Build-in sampling and hold circuit Internal self-bias reference voltage 45 mW very low power dissipation at 5MSPS +5V single power supply Available in 24 pin SOP Series EM19101M for 300 mil SOP EM19101S for 209 mil SOP APPLICATION Scanner and a wide range of fields where high speed A/D conversion is required in the digital communication. PIN ASSIGNMENT EM19101 OE DVSS D0 D1 D2 D3 D4 D5 D6 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 FUNCTIONAL BLOCK DIAGRAM 24 DV S S 2 23 VRB 3 22 V RBS 21 AVSS /O E 1 DVS S D0 D1 Reference voltage 4 Lower data latches Lower encoder (4bit) Lower Comparators with S/ H (4bit) D2 5 20 AVSS D3 6 19 VI N D4 7 18 AV DD D5 8 17 V RT D6 9 16 V RT S D7 10 15 AV DD 14 AV DD 13 DV DD Upper data latches Upper encoder (4bit) DV DD 1 1 CL K 1 2 Clock generator * This specification are subject to be changed without notice. Upper Comparators with S/ H (4bit) 4.23.1997 1 EM19101 8-BIT 5 MSPS A/D CONVERTER (CMOS) PIN DESCRIPTIONS Symbol Function OE DVSS D0 D1 D2 D3 D4 D5 D6 D7 DVDD CLK DVDD AVDD AVDD VRTS VRT AVDD VIN AVSS AVSS VRBS VRB DVSS Output enable Digital ground Data output bit 0 (LSB) Data output bit 1 Data output bit 2 Data output bit 3 Data output bit 4 Data output bit 5 Data output bit 6 Data output bit 7 (MSB) Digital power supply Clock input Digital power supply Analog power supply Analog power supply Top internal reference voltage Top reference voltaget Analog power supply Analog input voltage Analog ground Analog ground Bottom internal reference voltage Bottom reference voltage Digital ground TIMING DIAGRAM Exte rnal C lo c k Tra ns f er Cl o ck N+2 N N+1 Analog input Dat a o u t pu t N-3 N-2 * This specification are subject to be changed without notice. N+4 N+3 N-1 N N+1 N+2 4.23.1997 2 EM19101 8-BIT 5 MSPS A/D CONVERTER (CMOS) OUTPUT CODING Step 0 1 2 .... 124 125 .... 254 255 Analog Input (V) 0.607815 0.607815~0.6156250 0.6156250~0.6234375 .... 1.6000000~1.6078125 1.6078125~1.6156250 .... 2.5843750~2.5921875 2.5921875~ Digital Output Code 00000000 00000001 00000010 .... 10000000 10000001 .... 11111110 11111111 Conditions VRB=0.6V VRT=2.6V 1LSB=7.8125mV ABSOLUTE MAXIMUM RATINGS (TA=25°C) Items Supply voltage Operating temperature Input voltage Ref, Input voltage Sym. VDD TOPR VIN VRT,VRB Rating Unit 7 -20 to +65 VSS to VDD VSS to VDD V °C V V Rating Unit Recommended Poerating Conditions Items Supply voltage Reference input voltage Analog input voltage Sym. AVDD,AVSS DVDD,DVSS |DGND-AGND| VRB VRT VRT - VRB VIN 4.75 TO 5.25 V 0 to 100 0 and above VDD and below 1.0 to 3.0 VRB to VRT mV V V V V (FC=5MPS,VDD=5V,VRB=0.5V,VRT=2.5V,Ta=25°C External clock duty=40 to 60%) Parameter Sym. Conditions Min. Typ. Max. Maximum Conversion Speed FC Vin=0.6V to 2.6V fin=1kHz ramp 5 FC=5MSPS NTSC ramp wave input 10 15 Supply current IDD Reference pin current IREF 5.7 8.0 9.1 Analog input bandwidth BW 1 VIN=1.5V+0.07Vrms 11 Analog input capacitance CIN Reference resistance RREF 220 250 350 Short VRB and VRBS 0.55 0.6 0.65 Internal bias VRB VRT-VRB Short VRT and VRTS 1.9 2.0 2.1 -10 -35 -60 Offset Voltage EOT EOB 0 15 45 Digital input voltage VIH 4.0 1.0 VIL Digital input current IIH VDD=max. VIH=V DD 5 VIL=0V 5 I IL * This specification are subject to be changed without notice. Unit MSPS mA mA MHz pF Ω V mV V uA 4.23.1997 3 EM19101 8-BIT 5 MSPS A/D CONVERTER (CMOS) Parameter Digital output current Digital output current Sym. IOH IOL IOZH Output data delay Integral nonlinearity Differential nonlinearity Differential gain error TDL EL ED DG Differential phase error Aperture jitter Sampling delay Conditions OE=VSS, VDD=min. OE=VDD, VOH=VDD-0.5V VOL=0.4V VOH=VDD VOL=0V FC=5MSPS VIN=0.6V to 2.6V FC=5MSPS VIN=0.6V to 2.6V NTSC 40 IRE mod ramp, FC=14.3MSPS DP tAJ tDS Min. Typ. Max. Unit -1.1 mA 3.7 16 uA 16 25 40 ns 0.5 1.3 LSB ±0.3 ±0.5 LSB 1.0 0.5 30 4 % °C ps ns Application Note VDD,VSS To reduce noise effects, separate the analog and digital systems close to the device. For both the digital and analog VDD pins, use a ceramic capacitor of about 0.1uF set as close as possible to the pin to bypass to the respective GND’s. Analog input Compared with the flash type A/D converter, the input capacitance of the analog input is rather small. However it is necessary to conduct the drive with an amplifier featuring sufficient band and drive capability. When driving with an amplifier of low output impedance, parasite oscillation may occur. That may be prevented by inserting a resistance of about 100Ω in series between the amplifier output and A/D input. Clock input The clock line wiring should be as short as possible also, to avoid any interference with other signals, separate it from other circuits Reference input Voltage between VRT to VRB is compatible with the dynamic range of the analog input. Bypassing VRT and VRB pins to GND, by means of a capacitor about 0.1µF, stable characteristics are obtained. By shorting VRT and VRTS, VRB and VRBS, the self bias function that generates VRT=2.6V and VRB=0.6V, is activated. Timing Analog input is sampled with the falling edge of external clock and output as digital data with a delay of 2.5 clocks and with the following rising edge. The delay from the clock rising edge to the data output is about 25ns. OE pin By connecting OE to GND output mode is obtained. By connecting to VDD high impedance is obtained. * This specification are subject to be changed without notice. 4.23.1997 4 EM19101 8-BIT 5 MSPS A/D CONVERTER (CMOS) About latch up It is necessary that AVDD and DVDD pins be the common source of power supply. This is to avoid latch up due to the voltage difference between AVDD and DVDD pins when power is ON. * This specification are subject to be changed without notice. 4.23.1997 5 EM19101 8-BIT 5 MSPS A/D CONVERTER (CMOS) Application Circuit U2 U2 U3 * This specification are subject to be changed without notice. 4.23.1997 6