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

1.0

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.)

MAX

MIN

(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