ADC08351 8-Bit, 42 MSPS, 40 mW A/D Converter
November 2003
ADC08351 8-Bit, 42 MSPS, 40 mW A/D Converter
General Description
The ADC08351 is an easy to use low power, low cost, small size, 42 MSPS analog-to-digital converter that digitizes signals to 8 bits. The ADC08351 uses an unique architecture that achieves 7.2 Effective Bits with a 4.4 MHz input and 42 MHz clock frequency and 6.8 Effective Bits with a 21 MHz input and 42 MHz clock frequency. Output formatting is straight binary coding. To minimize system cost and power consumption, the ADC08351 requires minimal external components and includes input biasing to allow optional a.c. input signal coupling. The user need only provide a +3V supply and a clock. Many applications require no separate reference or driver components. The excellent dc and ac characteristics of this device, together with its low power consumption and +3V single supply operation, make it ideally suited for many video and imaging applications, including use in portable equipment. Total power consumption is reduced to less than 7 mW in the power-down mode. Furthermore, the ADC08351 is resistant to latch-up and the outputs are short-circuit proof. Fabricated on a 0.35 micron CMOS process, the ADC08351 is offered in TSSOP and LLP (a molded lead frame-based chip-scale package), and is designed to operate over the industrial temperature range of −40˚C to +85˚C. n Single +3V Operation n Power Down Feature n TRI-STATE Outputs
Key Specifications
j Resolution j Maximum Sampling Frequency j ENOB @ fCLK = 42 MHz, fIN = 4.4 MHz j Guaranteed No Missing Codes j Power Consumption
8 Bits 42 MSPS (min) 7.2 Bits (typ)
40 mW (typ); 48 mW (max) (Excluding Reference Current)
Applications
n n n n n n n n n Video Digitization Digital Still Cameras Set Top Boxes Digital Camcorders Communications Medical Imaging Personal Computer Video CCD Imaging Electro-Optics
Features
n Low Input Capacitance n Internal Sample-and-Hold Function
Pin Configuration
20-Pin TSSOP 24-Pin LLP (CSP)
10089501
Top View
10089534
Bottom View
© 2003 National Semiconductor Corporation
DS100895
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ADC08351
Ordering Information
ADC08351CIMTC ADC08351CIMTCX ADC08351CILQ ADC08351CILQX TSSOP TSSOP (tape & reel) LLP (tape & reel - 1, 000 units) LLP (tape & reel - 4, 500 units)
ADC08351 Block Diagram
10089502
Pin Descriptions and Equivalent Circuits
Pin No. 17 (17) Symbol Equivalent Circuit
(LLP pins in parentheses) Description
VIN
Analog signal input. Conversion range is 0.5 VP-P to 0.68 VA.
14 (14)
VREF
Positive reference voltage input. Operating range of this voltage is 0.75V to VA. This pin should be bypassed with a 10 µF tantalum or aluminum electrolytic capacitor and a 0.1 µF ceramic chip capacitor. CMOS/TTL compatible digital input that, when low, enables the digital outputs of the ADC08351. When high, the outputs are in a high impedance state. CMOS/TTL compatible digital clock input. VIN is sampled on the falling edge of CLK input. CMOS/TTL compatible digital input that, when high, puts the ADC08351 into the power down mode, where it consumes minimal power. When this pin is low, the ADC08351 is in the normal operating mode.
1 (22) 12 (11) 15 (15)
OE
CLK
PD
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ADC08351
Pin Descriptions and Equivalent Circuits (LLP pins in parentheses)
Pin No. Symbol Equivalent Circuit
(Continued)
Description
3 thru 10 (1 thru 8)
D0–D7
Conversion data digital output pins. D0 is the LSB, D7 is the MSB. Valid data is output just after the rising edge of the CLK input. These pins are enabled by bringing the OE pin low.
11, 13 (10, 12)
VD
Positive digital supply pin. Connect to a clean, quiet voltage source of +3V. VA and VD should have a common supply and be separately bypassed with a 10 µF tantalum or aluminum electrolytic capacitor and a 0.1 µF ceramic chip capacitor. See Section 3.0 for more information. The ground return for the digital supply. AGND and DGND should be connected together close to the ADC08351. Positive analog supply pin. Connected to a clean, quiet voltage source of +3V. VA and VD should have a common supply and be separately bypassed with a 10 µF tantalum or aluminum electrolytic capacitor and a 0.1 µF ceramic chip capacitor. See Section 3.0 for more information. The ground return for the analog supply. AGND and DGND should be connected together close to the ADC08351 package.
2, 20 (21, 23)
DGND
16 (16)
VA
18, 19 (18, 19)
AGND
3
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ADC08351
Absolute Maximum Ratings
2)
(Notes 1,
Package Dissipation at TA = 25˚C ESD Susceptibility (Note 5) Human Body Model Machine Model Soldering Temp., Infrared, 10 sec. (Note 6) Storage Temperature
(Note 4) 4000V 200V 235˚C −65˚C to +150˚C
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VA, VD) Voltage on Any Input or Output Pin Ground Difference (AGND–DGND) CLK, OE Voltage Range Digital Output Voltage (VOH, VOL) Input Current at Any Pin (Note 3) Package Input Current (Note 3) 4.2V −0.3V to 4.2V
Operating Ratings (Notes 1, 2)
Operating Temperature Range Supply Voltage (VA, VD) Ground Difference |DGND–AGND| VIN Voltage Range (VP-P) −40˚C TA ≤ +85˚C +2.7V to +3.6V 0V to 100 mV 0.5V to 0.68 VA
± 100 mV
−0.5 to (VA + 0.5V) VD to DGND
± 25 mA ± 50 mA
Converter Electrical Characteristics
The following specifications apply for VA = VD = +3.0 VDC, VREF = 2.4V, VIN = 1.63 VP-P, OE = 0V, CL = 20 pF, fCLK = 42 MHz, 50% duty cycle, unless otherwise specified. Boldface limits apply for TA = TMIN to TMAX: all other limits TA = 25˚C (Notes 7, 8) Symbol DC Accuracy INL DNL Integral Non Linearity Error Differential Non Linearity Missing Codes EZ EFS DP DG Zero Scale Offset Error Full Scale Offset Error Differential Phase Error Differential Gain Error fCLK = 20 MHz, Video Ramp Input fCLK = 20 MHz, Video Ramp Input (CLK LOW) (CLK HIGH) −17 −7 1.0 1.5 4 11 7.2 120 At pin 14 0.735 VA 7.7 PD = Low PD = High PD = Low, No Digital Output Load PD = High Excluding Reference Current, VIN = 0 VDC PD = Low (excluding reference current) PD = High (excluding reference current) 10.5 1 2.9 0.5 13.4 40.2 16 48 Parameter Conditions Typical (Note 9) Limits (Note 9) Units (Limits) LSB (max) LSB (max) LSB (min) (max) mV mV Degree % pF pF kΩ MHz V V mA mA mA mA mA mA (max) mW (max) mW
± 0.7 ± 0.6
± 1.4
+1.3 −1.0 0
Video Accuracy
Analog Input and Reference Characteristics CIN RIN FPBW VREF IREF VIN Input Capacitance RIN Input Resistance Full-Power Bandwidth Reference Input Voltage Reference Input Current VIN = 1.5V + 0.7 Vrms
Power Supply Characteristics IA ID Analog Supply Current Digital Supply Current Total Operating Current Power Consumption (active) Power Consumption (power down) CLK, OE Digital Input Characteristics VIH VIL IIH IIL Logical High Input Voltage Logical Low Input Voltage Logical High Input Current Logic Low Input Current VD = VA = 3V VD = VA = 3V VIH = VD = VA = 3.3V VIL = 0V, VD = VA = 3.3V
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