Datasheet

AD9945
–3–
Parameter Min Typ Max Unit Notes
CDS
Maximum Input Range before Saturation* 1.0 Vp-p
Allowable CCD Reset Transient* 500 mV See Input Waveform in Footnote
Maximum CCD Black Pixel Amplitude* 100 mV
VARIABLE GAIN AMPLIFIER (VGA)
Gain Control Resolution 1024 Steps
Gain Monotonicity Guaranteed
Gain Range
Minimum Gain 5.3 dB
Maximum Gain 40.0 41.5 dB
BLACK LEVEL CLAMP
Clamp Level Resolution 256 Steps
Clamp Level Measured at ADC Output
Minimum Clamp Level 0 LSB
Maximum Clamp Level 255 LSB
A/D CONVERTER
Resolution 12 Bits
Differential Nonlinearity (DNL) ± 0.5 LSB
No Missing Codes Guaranteed
Data Output Coding Straight Binary
Full-Scale Input Voltage 2.0 V
VOLTAGE REFERENCE
Reference Top Voltage (REFT) 2.0 V
Reference Bottom Voltage (REFB) 1.0 V
SYSTEM PERFORMANCE Specifications Include Entire Signal Chain
Gain Range
Low Gain (VGA Code = 0) 5.3 dB
Maximum Gain (VGA Code = 1023) 40.0 41.5 dB
Gain Accuracy ⴞ1.0 dB
Peak Nonlinearity, 500 mV Input Signal 0.1 % 12 dB Gain Applied
Total Output Noise 1.2 LSB rms AC Grounded Input, 6 dB Gain Applied
Power Supply Rejection (PSR) 40 dB
*Input Signal Characteristics defined as follows:
500mV TYP
RESET TRANSIENT
100mV TYP
OPTICAL BLACK PIXEL
1V TYP
INPUT SIGNAL RANGE
Specifications subject to change without notice.
SYSTEM SPECIFICATIONS
REV.
C
, AVDD = DVDD = DRVDD = 3.0 V, f = 40 MHz, Register 0xD = 0x838,
unless otherwise noted.)
MAXMIN
(T to T
SAMP
See Variable Gain Amplifier section for VGA gain equation
Low Gain Mode
¦1.5 0 +1.5
dB
See Table 1, Internal Register Map, for register information
See Figure 7 for VGA Gain Curve