AD AD9845AJST

a
Complete 12-Bit 30 MSPS
CCD Signal Processor
AD9845A
PRODUCT DESCRIPTION
FEATURES
30 MSPS Correlated Double Sampler (CDS)
4 dB 6 dB 6-Bit Pixel Gain Amplifier ( PxGA®)
2 dB to 36 dB 10-Bit Variable Gain Amplifier (VGA)
Low Noise Clamp Circuits
Analog Preblanking Function
12-Bit 30 MSPS A/D Converter
Auxiliary Inputs with VGA and Input Clamp
3-Wire Serial Digital Interface
3 V Single Supply Operation
Low Power: 140 mW @ 3 V Supply
48-Lead LQFP Package
The AD9845A is a complete analog signal processor for CCD
applications. It features a 30 MHz single-channel architecture
designed to sample and condition the outputs of interlaced and
progressive scan area CCD arrays. The AD9845A’s signal chain
consists of an input clamp, correlated double sampler (CDS),
Pixel Gain Amplifier (PxGA), digitally controlled variable gain
amplifier (VGA), black level clamp, and a 12-bit A/D converter.
Additional input modes are provided for processing analog
video signals.
The internal registers are programmed through a 3-wire
serial digital interface. Programmable features include gain
adjustment, black level adjustment, input configuration, and
power-down modes.
APPLICATIONS
Digital Still Cameras
Digital Video Camcorders
Industrial Imaging
The AD9845A operates from a single 3 V power supply, typically dissipates 140 mW, and is packaged in a 48-lead LQFP.
FUNCTIONAL BLOCK DIAGRAM
PBLK
AVDD
AVSS
4dB 6dB
HD
VD
CLPOB
COLOR
STEERING
DRVDD
CLP
DRVSS
CDS
CCDIN
2dB~36dB
PxGA
12
2:1
MUX
ADC
VGA
DOUT
CLP
6
BANDGAP
REFERENCE
CLPDM
10
AUX1IN
2:1
MUX
OFFSET
DAC
BUF
INTERNAL
BIAS
AUX2IN
VRT
VRB
CML
8
CONTROL
REGISTERS
CLP
DVDD
DIGITAL
INTERFACE
AD9845A
SL
SCK
INTERNAL
TIMING
SDATA
SHP
SHD
DVSS
DATACLK
PxGA is a registered trademark of Analog Devices, Inc.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2001
AD9845A–SPECIFICATIONS
GENERAL SPECIFICATIONS (T
MIN
to TMAX, AVDD = DVDD = 3.0 V, fDATACLK = 30 MHz, unless otherwise noted.)
Parameter
Min
TEMPERATURE RANGE
Operating
Storage
POWER SUPPLY VOLTAGE
Analog, Digital, Digital Driver
POWER CONSUMPTION
Normal Operation
Power-Down Modes
Fast Recovery Mode
Standby
Total Power-Down
Typ
Max
Unit
–20
–65
+85
+150
°C
°C
2.7
3.6
V
(Specified Under Each Mode of Operation)
90
5
1
MAXIMUM CLOCK RATE
mW
mW
mW
30
A/D CONVERTER
Resolution
Differential Nonlinearity (DNL)
No Missing Codes
Full-Scale Input Voltage
Data Output Coding
MHz
12
±0.5
Bits
LSB
Bits Guaranteed
V
±1.0
12
2.0
Straight Binary
VOLTAGE REFERENCE
Reference Top Voltage (VRT)
Reference Bottom Voltage (VRB)
2.0
1.0
V
V
Specifications subject to change without notice.
DIGITAL SPECIFICATIONS (DRVDD = 2.7 V, C = 20 pF unless otherwise noted.)
L
Parameter
Symbol
Min
LOGIC INPUTS
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
Input Capacitance
VIH
VIL
IIH
IIL
CIN
2.1
LOGIC OUTPUTS
High Level Output Voltage, IOH = 2 mA
Low Level Output Voltage, IOL = 2 mA
VOH
VOL
2.2
Typ
Max
0.6
10
10
10
0.5
Unit
V
V
µA
µA
pF
V
V
Specifications subject to change without notice.
–2–
REV. 0
AD9845A
CCD-MODE SPECIFICATIONS (T
MIN
Parameter
to TMAX, AVDD = DVDD = 3.0 V, fDATACLK = fSHP = fSHD = 30 MHz, unless otherwise noted.)
Min
POWER CONSUMPTION
MAXIMUM CLOCK RATE
CDS
Gain
Allowable CCD Reset Transient 1
Max Input Range Before Saturation 1
Max CCD Black Pixel Amplitude 1
PIXEL GAIN AMPLIFIER (PxGA)
Max Input Range
Max Output Range
Gain Control Resolution
Gain Monotonicity
Gain Range (Two’s Complement Coding)
Min Gain (PxGA Gain Code 32)
Max Gain (PxGA Gain Code 31)
VARIABLE GAIN AMPLIFIER (VGA)
Max Input Range
Max Output Range
Gain Control Resolution
Gain Monotonicity
Gain Range
Low Gain (VGA Gain Code 91)
Max Gain (VGA Gain Code 1023)
POWER-UP RECOVERY TIME
Fast Recovery Mode
Reference Standby Mode
Total Shutdown Mode
Power-Off Condition
Max
140
30
1.0
200
1.0
1.6
64
Guaranteed
See TPC 1 for Power Curves
See Input Waveform in Footnote 1
PxGA Gain at 4 dB
See Figure 28 for PxGA Gain Curve
–2
10
dB
dB
1.6
2.0
V p-p
V p-p
Steps
1024
Guaranteed
See Figure 29 for VGA Gain Curve
2
36
dB
dB
256
Steps
0
255
LSB
LSB
Measured at ADC Output
–0.5
–1
11
Specifications Include Entire Signal Chain
Use Equations on Page 18 to Calculate Gain
+0.5
0
12
0.1
0.6
40
+1
13
dB
dB
%
LSB rms
dB
VGA Gain Fixed at 2 dB (Code 91)
VGA Gain Fixed at 2 dB (Code 91)
12 dB Gain Applied
AC Grounded Input, 6 dB Gain Applied
Measured with Step Change on Supply
Normal Clock Signals Applied
0.1
1
3
15
ms
ms
ms
ms
1V MAX
INPUT SIGNAL RANGE
PxGA gain fixed at 4 dB (Code 63).
Specifications subject to change without notice.
REV. 0
mW
V p-p
V p-p
Steps
500mV TYP
RESET TRANSIENT
2
Notes
dB
mV
V p-p
mV
NOTES
1
Input Signal Characteristics defined as follows:
200mV MAX
OPTICAL BLACK PIXEL
Unit
MHz
0
500
BLACK LEVEL CLAMP
Clamp Level Resolution
Clamp Level
Min Clamp Level
Max Clamp Level
SYSTEM PERFORMANCE
Gain Accuracy (VGA Code 91 to 1023) 2
PxGA Gain Accuracy
Min Gain (PxGA Register Code 32)
Max Gain (PxGA Code 31)
Peak Nonlinearity, 500 mV Input Signal
Total Output Noise
Power Supply Rejection (PSR)
Typ
–3–
AD9845A–SPECIFICATIONS
AUX1-MODE SPECIFICATIONS
Parameter
(TMIN to TMAX, AVDD = DVDD = 3.0 V, fDATACLK = 30 MHz, unless otherwise noted.)
Min
Typ
POWER CONSUMPTION
100
MAXIMUM CLOCK RATE
30
INPUT BUFFER
Gain
Max Input Range
1.0
VGA
Max Output Range
Gain Control Resolution
Gain (Selected Using VGA Gain Register)
Min Gain
Max Gain
Max
Unit
mW
MHz
0
dB
V p-p
2.0
1023
V p-p
Steps
0
36
dB
dB
Specifications subject to change without notice.
AUX2-MODE SPECIFICATIONS
Parameter
(TMIN to TMAX, AVDD = DVDD = 3.0 V, fDATACLK = 30 MHz, unless otherwise noted.)
Min
Typ
POWER CONSUMPTION
MAXIMUM CLOCK RATE
100
30
INPUT BUFFER
VGA
Max Output Range
Gain Control Resolution
Gain (Selected Using VGA Gain Register)
Min Gain
Max Gain
Max
Unit
mW
MHz
(Same as AUX1-MODE)
2.0
ACTIVE CLAMP
Clamp Level Resolution
Clamp Level (Measured at ADC Output)
Min Clamp Level
Max Clamp Level
512
V p-p
Steps
0
18
dB
dB
256
Steps
0
255
LSB
LSB
Specifications subject to change without notice.
–4–
REV. 0
AD9845A
(CL = 20 pF, fSAMP = 30 MHz, CCD-Mode Timing in Figures 10 and 11, AUX-Mode Timing in Figure 7.
TIMING SPECIFICATIONS Serial Timing in Figures 26–29.)
Parameter
Symbol
Min
Typ
SAMPLE CLOCKS
DATACLK, SHP, SHD Clock Period
DATACLK Hi/Low Pulsewidth
SHP Pulsewidth
SHD Pulsewidth
CLPDM Pulsewidth
CLPOB Pulsewidth1
SHP Rising Edge to SHD Falling Edge
SHP Rising Edge to SHD Rising Edge
Internal Clock Delay
Inhibited Clock Period
tCONV
tADC
tSHP
tSHD
tCDM
tCOB
tS1
tS2
tID
tINH
32
13
5
5
4
2
0
13
33
16.7
8.3
8.3
10
20
8.3
16.7
3.0
DATA OUTPUTS
Output Delay
Output Hold Time
Pipeline Delay
SERIAL INTERFACE
Maximum SCK Frequency
SL to SCK Setup Time
SCK to SL Hold Time
SDATA Valid to SCK Rising Edge Setup
SCK Falling Edge to SDATA Valid Hold
SCK Falling Edge to SDATA Valid Read
Max
Unit
ns
ns
ns
ns
Pixels
Pixels
ns
ns
ns
ns
10
tOD
tH
7.0
fSCLK
tLS
tLH
tDS
tDH
tDV
10
10
10
10
10
10
14.5
7.6
9
16
ns
ns
Cycles
MHz
ns
ns
ns
ns
ns
NOTES
1
Minimum CLPOB pulsewidth is for functional operation only. Wider typical pulses are recommended to achieve low noise clamp performance.
Specifications subject to change without notice.
ORDERING GUIDE
ABSOLUTE MAXIMUM RATINGS
Parameter
AVDD1, AVDD2
DVDD1, DVDD2
DRVDD
Digital Outputs
SHP, SHD, DATACLK
CLPOB, CLPDM, PBLK
SCK, SL, SDATA
VRT, VRB, CMLEVEL
BYP1-4, CCDIN
Junction Temperature
Lead Temperature
(10 sec)
With
Respect
To
Min Max
AVSS
DVSS
DRVSS
DRVSS
DVSS
DVSS
DVSS
AVSS
AVSS
–0.3
–0.3
–0.3
–0.3
–0.3
–0.3
–0.3
–0.3
–0.3
+3.9
+3.9
+3.9
DRVDD + 0.3
DVDD + 0.3
DVDD + 0.3
DVDD + 0.3
AVDD + 0.3
AVDD + 0.3
150
300
Unit
V
V
V
V
V
V
V
V
V
°C
°C
Model
Temperature
Range
Package
Description
Package
Option
AD9845AJST
–20°C to +85°C
Thin Plastic
Quad Flatpack
(LQFP)
ST-48
THERMAL CHARACTERISTICS
Thermal Resistance
48-Lead LQFP Package
θJA = 92°C
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the AD9845A features proprietary ESD protection circuitry, permanent damage may occur on
devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
REV. 0
–5–
WARNING!
ESD SENSITIVE DEVICE
AD9845A
VRT
CML
THREE-STATE
DVSS
DVDD2
VRB
NC
SDATA
SL
NC
STBY
SCK
PIN CONFIGURATIONS
48 47 46 45 44 43 42 41 40 39 38 37
(LSB) D0
1
36
AUX1IN
35
AVSS
D2 3
34
AUX2IN
D3 4
33
AVDD2
32
BYP4
31
NC
30
CCDIN
D7 8
29
BYP2
D8 9
28
D9 10
27
BYP1
AVDD1
D10 11
(MSB) D11 12
26
PIN 1
IDENTIFIER
D1 2
D4 5
D5 6
AD9845A
D6 7
TOP VIEW
(Not to Scale)
AVSS
AVSS
CLPDM
VD
HD
PBLK
CLPOB
SHP
SHD
DVSS
DATACLK
DVDD1
DRVSS
13 14 15 16 17 18 19 20 21 22 23 24
DRVDD
NC = NO CONNECT
25
PIN FUNCTION DESCRIPTIONS
Pin Number
Name
Type
Description
1–12
13
14
15, 41
16
17
18
19
20
21
22
23
24
25, 26, 35
27
28
29
30
31
32
33
34
36
37
38
39
40
42
43
44
45
46
47
48
D0–D11
DRVDD
DRVSS
DVSS
DATACLK
DVDD1
HD
PBLK
CLPOB
SHP
SHD
CLPDM
VD
AVSS
AVDD1
BYP1
BYP2
CCDIN
NC
BYP4
AVDD2
AUX2IN
AUX1IN
CML
VRT
VRB
DVDD2
THREE-STATE
NC
STBY
NC
SL
SDATA
SCK
DO
P
P
P
DI
P
DI
DI
DI
DI
DI
DI
DI
P
P
AO
AO
AI
NC
AO
P
AI
AI
AO
AO
AO
P
DI
NC
DI
NC
DI
DI
DI
Digital Data Outputs
Digital Output Driver Supply
Digital Output Driver Ground
Digital Ground
Digital Data Output Latch Clock
Digital Supply
Horizontal Drive. Used with VD for Color Steering Control
Preblanking Clock Input
Black Level Clamp Clock Input
CDS Sampling Clock for CCD’s Reference Level
CDS Sampling Clock for CCD’s Data Level
Input Clamp Clock Input
Vertical Drive. Used with HD for Color Steering Control
Analog Ground
Analog Supply
Internal Bias Level Decoupling
Internal Bias Level Decoupling
Analog Input for CCD Signal
Internally Not Connected
Internal Bias Level Decoupling
Analog Supply
Analog Input
Analog Input
Internal Bias Level Decoupling
A/D Converter Top Reference Voltage Decoupling
A/D Converter Bottom Reference Voltage Decoupling
Digital Supply
Digital Output Disable. Active High
May be tied high or low. Do not leave floating.
Standby Mode, Active High. Same as Serial Interface
Internally Not Connected. May be Tied High or Low
Serial Digital Interface Load Pulse
Serial Digital Interface Data
Serial Digital Interface Clock
TYPE: AI = Analog Input, AO = Analog Output, DI = Digital Input, DO = Digital Output, P = Power.
–6–
REV. 0
AD9845A
DEFINITIONS OF SPECIFICATIONS
DIFFERENTIAL NONLINEARITY (DNL)
An ideal ADC exhibits code transitions that are exactly 1 LSB
apart. DNL is the deviation from this ideal value. Thus every code
must have a finite width. No missing codes guaranteed to 12-bit
resolution indicates that all 4096 codes, respectively, must be
present over all operating conditions.
PEAK NONLINEARITY
Peak nonlinearity, a full signal chain specification, refers to the
peak deviation of the output of the AD984x from a true straight
line. The point used as “zero scale” occurs 1/2 LSB before the
first code transition. “Positive full scale” is defined as a Level 1,
1/2 LSB beyond the last code transition. The deviation is measured
from the middle of each particular output code to the true straight
line. The error is then expressed as a percentage of the 2 V ADC
full-scale signal. The input signal is always appropriately gained up
to fill the ADC’s full-scale range.
TOTAL OUTPUT NOISE
in LSB, and represents the rms noise level of the total signal
chain at the specified gain setting. The output noise can be
converted to an equivalent voltage, using the relationship 1 LSB
= (ADC Full Scale/2N codes) when N is the bit resolution of the
ADC. For the AD9845A, 1 LSB is 500 µV.
POWER SUPPLY REJECTION (PSR)
The PSR is measured with a step change applied to the supply
pins. This represents a very high frequency disturbance on the
AD984x’s power supply. The PSR specification is calculated
from the change in the data outputs for a given step change in
the supply voltage.
INTERNAL DELAY FOR SHP/SHD
The internal delay (also called aperture delay) is the time delay
that occurs from when a sampling edge is applied to the AD984x
until the actual sample of the input signal is held. Both SHP and
SHD sample the input signal during the transition from low to
high, so the internal delay is measured from each clock’s rising
edge to the instant the actual internal sample is taken.
The rms output noise is measured using histogram techniques.
The standard deviation of the ADC output codes is calculated
EQUIVALENT INPUT CIRCUITS
DVDD
ACVDD
330
60
ACVSS
ACVSS
DVSS
Figure 1. Digital Inputs—SHP, SHD, DATACLK, CLPOB,
CLPDM, HD, VD, PBLK, SCK, SL
DVDD
Figure 3. CCDIN (Pin 30)
DRVDD
DATA
DVDD
DVDD
DATA IN
THREESTATE
DOUT
330
DATA OUT
RNW
DVSS
DVSS
DVSS
DRVSS
Figure 2. Data Outputs—D0–D11
REV. 0
Figure 4. SDATA (Pin 47)
–7–
DVSS
AD9845A–Typical Performance Characteristics
160
15
VDD = 3.3V
OUTPUT NOISE – LSB
POWER DISSIPATION – mW
150
140
VDD = 3.0V
130
120
10
5
VDD = 2.7V
110
100
10
0
30
20
SAMPLE RATE – MHz
0
200
600
400
VGA GAIN CODE – LSB
800
1000
TPC 3. Output Noise vs. VGA Gain
TPC 1. Power vs. Sample Rate
0.5
0.25
0
–0.25
–0.5
0
500
1000
1500
2000
2500
3000
3500
4000
TPC 2. Typical DNL Performance
–8–
REV. 0
AD9845A
CCD-MODE AND AUX MODE TIMING
CCD
SIGNAL
N
tID
N+1
N+2
N+9
N+10
tID
SHP
tS1
tS2
tCP
SHD
tINH
DATACLK
tOD
OUTPUT
DATA
tH
N–10
N–9
N–8
N–1
N
NOTES:
1. RECOMMENDED PLACEMENT FOR DATACLK RISING EDGE IS BETWEEN THE SHD RISING EDGE AND NEXT SHP FALLING EDGE.
2. CCD SIGNAL IS SAMPLED AT SHP AND SHD RISING EDGES.
Figure 5. CCD-Mode Timing
EFFECTIVE PIXELS
HORIZONTAL
BLANKING
OPTICAL BLACK PIXELS
DUMMY PIXELS
EFFECTIVE PIXELS
CCD
SIGNAL
CLPOB
CLPDM
PBLK
OUTPUT
DATA
OB PIXEL DATA
EFFECTIVE PIXEL DATA
DUMMY BLACK
EFFECTIVE DATA
NOTES:
1. CLPOB AND CLPDM WILL OVERWRITE PBLK. PBLK WILL NOT AFFECT CLAMP OPERATION IF OVERLAPPING CLPDM AND/OR CLPOB.
2. PBLK SIGNAL IS OPTIONAL.
3. DIGITAL OUTPUT DATA WILL BE ALL ZEROS DURING PBLK. OUTPUT DATA LATENCY IS 9 DATACLK CYCLES.
Figure 6. Typical CCD-Mode Line Clamp Timing
N+9
N
N+1
N+8
tID
VIDEO
SIGNAL
N+2
tCP
DATACLK
tOD
OUTPUT
DATA
N–10
tH
N–9
N–8
N–1
Figure 7. AUX-Mode Timing
REV. 0
–9–
N
AD9845A
PIXEL GAIN AMPLIFIER (PxGA) TIMING
FRAME n
VD
0101...
LINE 0
HD
2323...
LINE 1
FRAME n+1
0101...
0101...
LINE 2
LINE m–1
LINE m
0101...
2323...
LINE 0
LINE 1
LINE 2
LINE m–1
LINE m
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2, 3 = GAIN3
Figure 8. PxGA Mode 1 (Mosaic Separate) Frame/Line Gain Register Sequence
5 PIXEL MIN
VD
HD
3ns MIN
3ns MIN
SHP
GAINX
PxGA GAIN
GAIN0
GAIN1
GAIN0
GAINX
GAIN2
GAIN3
NOTES:
1. MINIMUM PULSEWIDTH FOR HD AND VD IS 5 PIXEL CYCLES.
2. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES. MINIMUM SET-UP TIME IS 3ns.
3. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING EDGE WILL RESET TO 0101.
4. EVERY HD RISING EDGE WITHOUT A PREVIOUS VD RISING EDGE WILL ALTERNATE BETWEEN 0101... AND 2323.
Figure 9. PxGA Mode 1 (Mosaic Separate) Detailed Timing
EVEN FIELD
VD
0101...
LINE 0
HD
2323...
LINE 1
ODD FIELD
0101...
0101...
LINE 2
LINE m–1
LINE m
LINE 0
0101...
2323...
LINE 1
LINE 2
LINE m–1
LINE m
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2, 3 = GAIN3
Figure 10. PxGA Mode 2 (Interlace) Frame/Line Gain Register Sequence
VD
5 PIXEL MIN
HD
3ns MIN
3ns MIN
SHP
PxGA
GAIN
GAINX
GAIN0
GAIN1
GAIN0
GAINX
GAIN2
GAIN3
NOTES:
1. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES.
2. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING OR FALLING EDGE WILL RESET TO 0101.
3. EVERY HD RISING EDGE WITHOUT A PREVIOUS VD RISING EDGE WILL ALTERNATE BETWEEN 0101... AND 2323.
Figure 11. PxGA Mode 2 (Interlace) Detailed Timing
–10–
REV. 0
AD9845A
LINE n
VD
LINE n+1
012012012...
...01201
012012012...
HD
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2
Figure 12. PxGA Mode 3 (3-Color) Frame/Line Gain Register Sequence
5 PIXEL MIN
VD
5 PIXEL MIN
HD
3ns MIN
SHP
GAINX
PxGA GAIN
GAIN0
GAIN1
GAIN2
GAIN0
GAINX
GAIN0
GAIN1
GAIN0
GAIN1
NOTES:
1. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES.
2. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING EDGE WILL RESET TO 012012.
Figure 13. PxGA Mode 3 (3-Color) Detailed Timing
LINE n
VD
LINE n+1
01230123012...
...01230
012301230123...
HD
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2, 3 = GAIN3
Figure 14. PxGA Mode 4 (4-Color) Frame/Line Gain Register Sequence
5 PIXEL MIN
VD
5 PIXEL MIN
HD
3ns MIN
SHP
PxGA GAIN
GAINX
GAIN0
GAIN1
GAIN2
GAIN0
NOTES:
1. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES.
2. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING EDGE WILL RESET TO 01230123.
Figure 15. PxGA Mode 4 (4-Color) Detailed Timing
REV. 0
–11–
GAINX
AD9845A
ODD FIELD
VD
EVEN FIELD
0101...
0101...
LINE 0
HD
2323...
0101...
LINE 1
LINE 2
LINE m–1
LINE m
LINE 0
2323...
2323...
LINE 1
LINE 2
LINE m–1
LINE m
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2, 3 = GAIN3
Figure 16. PxGA Mode 5 (VD Selected) Frame/Line Gain Register Sequence
VD
5 PIXEL MIN
HD
3ns MIN
3ns MIN
SHP
GAINX
PxGA GAIN
GAIN0
GAIN1
GAIN0
GAINX
GAIN2
GAIN3
NOTES:
1. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES.
2. EVERY HD RISING EDGE WITH A PREVIOUS VD FALLING EDGE WILL RESET TO 0101.
3. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING EDGE WILL RESET TO 2323.
4. EVERY HD RISING EDGE WITHOUT A PREVIOUS VD RISING EDGE WILL REPEAT EITHER 0101... (EVEN) OR 2323 ... (ODD).
Figure 17. PxGA Mode 5 (VD Selected) Detailed Timing
FRAME n
VD
0101...
LINE 0
HD
1212...
FRAME n+1
0101...
LINE 1
LINE 2
0101...
LINE m–1
LINE m
LINE 0
1212...
0101...
LINE 1
LINE 2
LINE m–1
LINE m
NOTE: 0 = GAIN0, 1 = GAIN1, 2 = GAIN2
Figure 18. PxGA Mode 6 (Mosaic Repeat) Frame/Line Gain Register Sequence
5 PIXEL MIN
VD
HD
3ns MIN
3ns MIN
SHP
PxGA GAIN
GAINX
GAIN0
GAIN1
GAIN0
GAINX
GAIN1
GAIN2
NOTES:
1. MINIMUM PULSEWIDTH FOR HD AND VD IS 5 PIXEL CYCLES.
2. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES. MINIMUM SET-UP TIME IS 3ns.
3. EVERY HD RISING EDGE WITH A PREVIOUS VD RISING EDGE WILL RESET TO 0101.
4. EVERY HD RISING EDGE WITHOUT A PREVIOUS VD RISING EDGE WILL ALTERNATE BETWEEN 0101... AND 1212.
Figure 19. PxGA Mode 6 (Mosaic Repeat) Detailed Timing
–12–
REV. 0
AD9845A
VD
HD
3ns MIN
3ns MIN
SHP
PxGA GAIN
GAIN0
GAIN0
GAIN1
GAIN2
NOTES:
1. BOTH VD AND HD ARE INTERNALLY UPDATED AT SHP RISING EDGES.
2. VD = 0 AND HD = 0 SELECTS GAIN0.
3. VD = 0 AND HD = 1 SELECTS GAIN1.
4. VD = 1 AND HD = 0 SELECTS GAIN2.
5. VD = 1 AND HD = 1 SELECTS GAIN3.
Figure 20. PxGA Mode 7 (User-Specified) Detailed Timing
REV. 0
–13–
GAIN3
AD9845A
SERIAL INTERFACE TIMING AND INTERNAL REGISTER DESCRIPTION
Table I. Internal Register Map
Register
Name
Address
A0 A1 A2
Operation
0
0
0
Channel Select Power-Down
CCD/AUX1/2 Modes
VGA Gain
1
0
0
LSB
Clamp Level
0
1
0
LSB
Control
1
1
0
Color Steering Mode
Selection
PxGA Gain0
0
0
1
LSB
MSB
PxGA Gain1
1
0
1
LSB
PxGA Gain2
0
1
1
PxGA Gain3
1
1
1
D0
D1
Data Bits
D3
D4
D2
D5
Software OB Clamp
Reset
On/Off
D6
D7
D8
D9
D10
0*
1**
0*
0*
0*
MSB
X
MSB
X
X
X
0*
0*
ThreeState
X
X
X
X
X
X
MSB
X
X
X
X
X
LSB
MSB
X
X
X
X
X
LSB
MSB
X
X
X
X
X
PxGA
On/Off
Clock Polarity Select for
SHP/SHD/CLP/DATA
*Internal use only. Must be set to zero.
**Must be set to one.
RNW
0
SDATA
TEST BIT
A0
tDS
A1
A2
0
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
tDH
SCK
tLS
tLH
SL
NOTES:
1. SDATA BITS ARE INTERNALLY LATCHED ON THE RISING EDGES OF SCK.
2. RNW = READ-NOT WRITE. SET LOW FOR WRITE OPERATION.
3. TEST BITS = INTERNAL USE ONLY. MUST BE SET LOW.
4. SYSTEM UPDATE OF LOADED REGISTERS OCCURS ON SL RISING EDGE.
Figure 21. Serial Write Operation
RNW
1
SDATA
TEST BIT
A0
tDS
tDH
A1
0
0
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
tDV
SCK
tLS
tLH
SL
NOTES:
1. RNW = READ-NOT WRITE. SET HIGH FOR READ OPERATION.
2. TEST BITS = INTERNAL USE ONLY. MUST BE SET LOW.
3. SERIAL DATA FROM THE SELECTED REGISTER IS VALID STARTING AFTER THE 5TH SCK FALLING EDGE, AND IS UPDATED ON
SCK FALLING EDGES.
Figure 22. Serial Readback Operation
–14–
REV. 0
AD9845A
RNW A0 A1
SDATA
0
0
A2
0
0
0
11 BITS
OPERATION
10 BITS
ACG GAIN
...
...
D0
D10 D0
...
SCK
2
1
3
4
5
8 BITS
CLAMP LEVEL
D9
...
D0
16
D0
17
26
...
6 BITS
PxGA GAIN0
D9
...
D0
27
34
D5
6 BITS
PxGA GAIN1
D0
...
...
...
...
6
D7
10 BITS
CONTROL
35
44
...
D5
6 BITS
PxGA GAIN2
D0
...
50
51
...
D0
D5
56
57
D5
...
...
...
45
6 BITS
PxGA GAIN3
62
63
68
SL
...
NOTES:
1. ANY NUMBER OF ADJACENT REGISTERS MAY BE LOADED SEQUENTIALLY, BEGINNING WITH THE LOWEST ADDRESS AND INCREMENTING ONE ADDRESS AT A TIME.
2. WHEN SEQUENTIALLY LOADING MULTIPLE REGISTERS, THE EXACT REGISTER LENGTH (SHOWN ABOVE) MUST BE USED FOR EACH REGISTER.
3. ALL LOADED REGISTERS WILL BE SIMULTANEOUSLY UPDATED WITH THE RISING EDGE OF SL.
Figure 23. Continuous Serial Write Operation to All Registers
RNW
A0
A1
A2
0
0
0
1
SDATA
0
D0
D1
D2
D3
D4
D5
D0
D1
D2
D3
PxGA GAIN3
PxGA GAIN2
PxGA GAIN1
PxGA GAIN0
D4
D5
D0
...
D5
...
D0
...
...
SCK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
D5
23
24
SL
29
...
Figure 24. Continuous Serial Write Operation to All PxGA Gain Registers
Table II. Operation Register Contents (Default Value x000)
D10
D9
D8
D7
D6
0*
0*
0*
1** 0*
Optical Black Clamp
D5
Reset
D4
Power-Down Modes
D3 D2
Channel Selection
D1 D0
0 Enable Clamping
1 Disable Clamping
0 Normal
1 Reset All Registers
to Default
0
0
1
1
0
0
1
1
0
1
0
1
Normal Power
Fast Recovery
Standby
Total Power-Down
0
1
0
1
CCD Mode
AUX1 Mode
AUX2 Mode
Test Only
*Must be set to zero.
**Set to one.
Table III. VGA Gain Register Contents (Default Value x096)
D10
MSB
D9
D8
D7
D6
D5
D4
D3
D2
D1
LSB
D0
X
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
•
•
•
1
1
1
1
1
1
1
1
1
1
0
1
REV. 0
–15–
Gain (dB)
2.0
•
•
•
35.965
36.0
AD9845A
Table IV. Clamp Level Register Contents (Default Value x080)
D10
D9
D8
X
X
X
MSB
D7
D6
D5
D4
D3
D2
D1
LSB
D0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
Clamp Level (LSB)
1
1
1
1
1
1
1
0
0
1
2
•
•
•
254
1
1
1
1
1
1
1
1
255
•
•
•
Table V. Control Register Contents (Default Value x000)
Data Out
D10 D9
X
DATACLK
D8 D7 D6
0 Enable
0* 0*
1 Three-State
CLP/PBLK
D5
SHP/SHD
D4
PxGA
D3**
0 Rising Edge Trigger 0 Active Low 0 Active Low
1 Falling Edge Trigger 1 Active High 1 Active High
Color Steering Modes
D2 D1 D0
0 Disable 0
1 Enable 0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Steering Disabled
Mosaic Separate
Interlace
3-Color
4-Color
VD Selected
Mosaic Repeat
User Specified
*Must be set to zero.
**When D3 = 0 (PxGA disabled) the PxGA gain is fixed to 4 dB.
Table VI. PxGA Gain Registers for Gain0, Gain1, Gain2, Gain3 (Default Value x000)
D10
D9
D8
D7
D6
MSB
D5
D4
D3
X
X
X
X
X
0
1
1
D2
D1
LSB
D0
1
1
1
•
•
•
0
1
0
1
0
1
0
0
+10.0
•
•
•
0
1
0
1
0
1
•
•
•
1
Gain (dB)*
+4.3
+4.0
•
•
•
0
0
0
–2.0
*Control Register Bit D3 must be set High (PxGA Enable) to use the PxGA Gain Registers.
–16–
REV. 0
AD9845A
CIRCUIT DESCRIPTION AND OPERATION
gain change on the system black level, usually called the “gain
step.” Another advantage of removing this offset at the input
stage is to maximize system headroom. Some area CCDs have
large black level offset voltages, which, if not corrected at the
input stage, can significantly reduce the available headroom in
the internal circuitry when higher VGA gain settings are used.
The AD9845A signal processing chain is shown in Figure 25.
Each processing step is essential in achieving a high-quality
image from the raw CCD pixel data.
DC Restore
To reduce the large dc offset of the CCD output signal, a dcrestore circuit is used with an external 0.1 µF series coupling
capacitor. This restores the dc level of the CCD signal to approximately 1.5 V, to be compatible with the 3 V single supply of
the AD9845A.
Horizontal timing is shown in Figure 6. It is recommended
that the CLPDM pulse be used during valid CCD dark pixels.
CLPDM may be used during the optical black pixels, either
together with CLPOB or separately. The CLPDM pulse should
be a minimum of 4 pixels wide.
Correlated Double Sampler
The CDS circuit samples each CCD pixel twice to extract the
video information and reject low-frequency noise. The timing
shown in Figure 5 illustrates how the two CDS clocks, SHP
and SHD, are used to sample the reference level and data level
of the CCD signal respectively. The CCD signal is sampled on
the rising edges of SHP and SHD. Placement of these two clock
signals is critical in achieving the best performance from the CCD.
An internal SHP/SHD delay (tID) of 3 ns is caused by internal
propagation delays.
PxGA
The PxGA provides separate gain adjustment for the individual
color pixels. A programmable gain amplifier with four separate
values, the PxGA has the capability to “multiplex” its gain value
on a pixel-to-pixel basis. This allows lower output color pixels to
be gained up to match higher output color pixels. Also, the PxGA
may be used to adjust the colors for white balance, reducing the
amount of digital processing that is needed. The four different gain
values are switched according to the “Color Steering” circuitry.
Seven different color steering modes for different types of CCD
color filter arrays are programmed in the AD984x’s Control Register. For example, Mosaic Separate steering mode accommodates
the popular “Bayer” arrangement of Red, Green, and Blue filters
(see Figure 26).
Input Clamp
A line-rate input clamping circuit is used to remove the CCD’s
optical black offset. This offset exists in the CCD’s shielded black
reference pixels. Unlike some AFE architectures, the AD9845A
removes this offset in the input stage to minimize the effect of a
VD
3
COLOR
STEERING
HD
PxGA MODE
SELECTION
2
GAIN0
4:1
MUX
DC RESTORE
6
GAIN1
GAIN2
PxGA GAIN
REGISTERS
INTERNAL
VREF
GAIN3
2V FULL SCALE
2dB TO 36dB
0.1F
CCDIN
CDS
PxGA
12
12-BIT
ADC
VGA
DOUT
–2dB TO +10dB
INPUT OFFSET
CLAMP
10
CLPDM
VGA GAIN
REGISTER
8-BIT
DAC
CLPOB
OPTICAL BLACK
CLAMP
DIGITAL
FILTERING
8
CLAMP LEVEL
REGISTER
Figure 25. CCD-Mode Block Diagram
REV. 0
–17–
AD9845A
for the AD9845A is 6 dB to 40 dB. The minimum gain of 6 dB
is needed to match a 1 V input signal with the ADC full-scale
range of 2 V. When compared to 1 V full-scale systems (such as
ADI’s AD9803), the equivalent gain range is 0 dB to 34 dB.
MOSAIC SEPARATE COLOR
STEERING MODE
CCD: PROGRESSIVE BAYER
R
Gr
R
Gr
LINE0
GAIN0, GAIN1, GAIN0, GAIN1 ...
Gb
B
Gb
B
LINE1
GAIN2, GAIN3, GAIN2, GAIN3 ...
R
Gr
R
Gr
LINE2
GAIN0, GAIN1, GAIN0, GAIN1 ...
Gb
B
Gb
B
The VGA gain curve is divided into two separate regions. When
the VGA Gain Register code is between 0 and 511, the curve
follows a (1 + x)/(1 – x) shape, which is similar to a “linear-indB” characteristic. From code 512 to code 1023, the curve follows
a “linear-in-dB” shape. The exact VGA gain can be calculated
for any Gain Register value by using the following two equations:
Figure 26. CCD Color Filter Example: Progressive Scan
CCD: INTERLACED BAYER
EVEN FIELD
VD SELECTED COLOR
STEERING MODE
R
Gr
R
Gr
LINE0
GAIN0, GAIN1, GAIN0, GAIN1 ...
R
Gr
R
Gr
LINE1
GAIN0, GAIN1, GAIN0, GAIN1 ...
R
Gr
R
Gr
LINE2
GAIN0, GAIN1, GAIN0, GAIN1 ...
R
Gr
R
Gr
Code Range
0–511
512 –1023
Gain Equation (dB)
Gain = 20 log10 ([658 + code]/[658 – code]) – 0.4
Gain = (0.0354)(code) – 0.4
As shown in the CCD Mode Specifications, only the VGA gain
range from 2 dB to 36 dB has tested and guaranteed accuracy.
This corresponds to a VGA gain code range of 91 to 1023. The
Gain Accuracy Specifications also include the PxGA gain of 4 dB,
for a total gain range of 6 dB to 40 dB.
ODD FIELD
36
B
Gb
B
LINE0
GAIN2, GAIN3, GAIN2, GAIN3 ...
Gb
B
Gb
B
LINE1
GAIN2, GAIN3, GAIN2, GAIN3 ...
Gb
B
Gb
B
LINE2
GAIN2, GAIN3, GAIN2, GAIN3 ...
Gb
B
Gb
B
30
VGA GAIN – dB
Gb
Figure 27. CCD Color Filter Example: Interlaced
The same Bayer pattern can also be interlaced, and the VD
Selected mode should be used with this type of CCD (see Figure 27). The Color Steering performs the proper multiplexing of
the R, G, and B gain values (loaded into the PxGA gain registers), and is synchronized by the user with vertical (VD) and
horizontal (HD) sync pulses. For more detailed information, see
the PxGA Timing section. The PxGA gain for each of the four
channels is variable from –2 dB to +10 dB, controlled in 64 steps
through the serial interface. The PxGA gain curve is shown in
Figure 28.
10
PxGA GAIN – dB
8
6
4
2
0
–2
32
(100000)
40
48
56
0
8
16
24
31
(011111)
PxGA GAIN REGISTER CODE
Figure 28. PxGA Gain Curve
Variable Gain Amplifier
The VGA stage provides a gain range of 2 dB to 36 dB, programmable with 10-bit resolution through the serial digital interface.
Combined with 4 dB from the PxGA stage, the total gain range
24
18
12
6
0
0
127
255
383
511
639
767
VGA GAIN REGISTER CODE
895
1023
Figure 29. VGA Gain Curve (Gain from PxGA Not Included)
Optical Black Clamp
The optical black clamp loop is used to remove residual offsets
in the signal chain, and to track low-frequency variations in the
CCD’s black level. During the optical black (shielded) pixel
interval on each line, the ADC output is compared with a fixed
black level reference, selected by the user in the Clamp Level
Register. Any value between 0 LSB and 255 LSB may be programmed, with 8-bit resolution. The resulting error signal is
filtered to reduce noise, and the correction value is applied to
the ADC input through a D/A converter. Normally, the optical
black clamp loop is turned on once per horizontal line, but this
loop can be updated more slowly to suit a particular application.
If external digital clamping is used during the post processing,
the AD9845A optical black clamping may be disabled using Bit
D5 in the Operation Register (see Serial Interface Timing and
Internal Register Description section). When the loop is disabled,
the Clamp Level Register may still be used to provide programmable offset adjustment.
Horizontal timing is shown in Figure 6. The CLPOB pulse
should be placed during the CCD’s optical black pixels. It is
recommended that the CLPOB pulse duration be at least 20
pixels wide to minimize clamp noise. Shorter pulsewidths may be
used, but clamp noise may increase, and the ability to track
low-frequency variations in the black level will be reduced.
–18–
REV. 0
AD9845A
A/D Converter
The VGA gains up the signal level with respect to the 0.4 V bias
level. Signal levels above the bias level will be further increased
to a higher ADC code, while signal levels below the bias level
will be further decreased to a lower ADC code.
The AD9845A uses high-performance ADC architecture, optimized for high speed and low power. Differential Nonlinearity
(DNL) performance is typically better than 0.5 LSB, as shown in
TPC 2. Instead of the 1 V full-scale range used by the earlier
AD9801 and AD9803 products from Analog Devices, the
AD9845A’s ADC uses a 2 V input range. Better noise performance results from using a larger ADC full-scale range (see
TPC 3).
AUX2 Mode
For sampling video-type waveforms, such as NTSC and PAL
signals, the AUX2 channel provides black level clamping, gain
adjustment, and A/D conversion. Figure 31 shows the circuit
configuration for using the AUX2 channel input (Pin 34). A
external 0.1 µF blocking capacitor is used with the on-chip video
clamp circuit, to level-shift the input signal to a desired reference level. The clamp circuit automatically senses the most
negative portion of the input signal, and adjusts the voltage
across the input capacitor. This forces the black level of the
input signal to be equal to the value programmed into the Clamp
Level register (see Serial Interface Register Description). The VGA
provides gain adjustment from 0 dB to 18 dB. The same VGA
Gain register is used, but only the 9 MSBs of the gain register
are used (see Table VII.)
AUX1 Mode
For applications that do not require CDS, the AD9845A can be
configured to sample ac-coupled waveforms. Figure 30 shows
the circuit configuration for using the AUX1 channel input
(Pin 36). A single 0.1 µF ac-coupling capacitor is needed between
the input signal driver and the AUX1IN pin. An on-chip dc-bias
circuit sets the average value of the input signal to approximately
0.4 V, which is referenced to the midscale code of the ADC.
The VGA Gain register provides a gain range of 0 dB to 36 dB in
this mode of operation (see VGA Gain Curve, Figure 29).
0.8V
0.4V
??V
5k
0.1F
0dB TO 36dB
AUX1IN
INPUT SIGNAL
VGA
MIDSCALE
10
0.4V
0.4V
ADC
VGA GAIN
REGISTER
Figure 30. AUX1 Circuit Configuration
VGA GAIN
REGISTER
9
0dB TO 18dB
BUFFER
AUX2IN
VIDEO
SIGNAL
ADC
VGA
0.1F
CLAMP LEVEL
VIDEO CLAMP
CIRCUIT
LPF
8
CLAMP LEVEL
REGISTER
Figure 31. AUX2 Circuit Configuration
Table VII. VGA Gain Register Used for AUX2-Mode
D10
X
REV. 0
MSB
D9
D8
D7
D6
D5
D4
D3
D2
D1
LSB
D0
0
1
X
0
X
0
X
0
X
0
X
0
X
0
X
0
X
0
1
1
1
1
X
0
•
•
•
1
1
1
1
1
1
–19–
Gain (dB)
0.0
0.0
•
•
•
18.0
AD9845A
APPLICATIONS INFORMATION
The AD9845A is a complete Analog Front End (AFE) product
for digital still camera and camcorder applications. As shown in
Figure 32, the CCD image (pixel) data is buffered and sent to
the AD9845A analog input through a series input capacitor.
The AD9845A performs the dc restoration, CDS, gain adjustment, black level correction, and analog-to-digital conversion.
The AD9845A’s digital output data is then processed by the
image processing ASIC. The internal registers of the AD984x—
used to control gain, offset level, and other functions—are
programmed by the ASIC or microprocessor through a 3-wire
serial digital interface. A system timing generator provides the
clock signals for both the CCD and the AFE.
AD9845A
CCD
VOUT
ADCOUT
0.1F
CCDIN
REGISTER
DATA
BUFFER
DIGITAL
OUTPUTS
SERIAL
INTERFACE
DIGITAL IMAGE
PROCESSING
ASIC
CDS/CLAMP
TIMING
V-DRIVE
CCD
TIMING
TIMING
GENERATOR
Figure 32. System Applications Diagram
–20–
REV. 0
AD9845A
3V
ANALOG SUPPLY
0.1F
1.0F
3
CML
VRT
DVDD2
VRB
0.1F
DVSS
RSTB
THREE-STATE
NC
STBY
SL
SDATA
1.0F
SCK
SERIAL
INTERFACE
48 47 46 45 44 43 42 41 40 39 38 37
D0 1
D1 2
36
PIN 1
IDENTIFIER
35
D2 3
D3
34
D4
5
D5
6
D6
7
D7
D9
D10
(MSB) D11
0.1F
3V
ANALOG SUPPLY
0.1F
32
AD9845A
31
TOP VIEW
(Not to Scale)
30
8
29
9
28
NC
CCDIN
CCD SIGNAL
BYP2
BYP1
0.1F
0.1F
AVDD1
AVSS
26
AVSS
10
27
11
12
25
12
0.1F
0.1F
3V
ANALOG SUPPLY
CLPDM
VD
SHD
CLPOB
SHP
HD
PBLK
DVSS
DATACLK
DVDD1
3V
DRIVER
SUPPLY
DRVSS
13 14 15 16 17 18 19 20 21 22 23 24
DRVDD
DATA
OUTPUTS
AUX2IN
AVDD2
33
BYP4
4
D8
AUX1IN
AVSS
NC = NO CONNECT
0.1F
8
CLOCK
INPUTS
0.1F
3V
ANALOG SUPPLY
Figure 33. Recommended Circuit Configuration for CCD-Mode
Internal Power-On Reset Circuitry
After power-on, the AD9845A will automatically reset all internal registers and perform internal calibration procedures. This
takes approximately 1 ms to complete. During this time, normal
clock signals and serial write operations may occur. However,
serial register writes will be ignored until the internal reset operation is completed. Pin 43 (formerly RSTB on the AD984x non-A
products) is no longer used for the reset operation. Toggling Pin
43 in the AD9845A will have no effect.
Grounding and Decoupling Recommendations
As shown in Figure 33, a single ground plane is recommended
for the AD9845A. This ground plane should be as continuous
as possible, particularly around Pins 25 through 39. This will
ensure that all analog decoupling capacitors provide the lowest
REV. 0
possible impedance path between the power and bypass pins and
their respective ground pins. All decoupling capacitors should
be located as close as possible to the package pins. A single clean
power supply is recommended for the AD9845A, but a separate
digital driver supply may be used for DRVDD (Pin 13). DRVDD
should always be decoupled to DRVSS (Pin 14), which should
be connected to the analog ground plane. Advantages of using
a separate digital driver supply include using a lower voltage
(2.7 V) to match levels with a 2.7 V ASIC, reducing digital power
dissipation, and reducing potential noise coupling. If the digital
outputs (Pins 3–12) must drive a load larger than 20 pF, buffering is recommended to reduce digital code transition noise.
Alternatively, placing series resistors close to the digital output pins may also help reduce noise.
–21–
AD9845A
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
0.063 (1.60)
MAX
0.354 (9.00) BSC SQ
0.030 (0.75)
0.018 (0.45)
37
48
36
1
0.276
(7.00)
BSC
SQ
TOP VIEW
(PINS DOWN)
0
MIN
12
25
13
0.019 (0.5)
BSC
0.008 (0.2)
0.004 (0.09)
24
0.011 (0.27)
0.006 (0.17)
0.057 (1.45)
0.053 (1.35)
7
0
0.006 (0.15) SEATING
0.002 (0.05) PLANE
PRINTED IN U.S.A.
COPLANARITY
0.003 (0.08)
C02385–2.5–1/01 (rev. 0)
48-Lead LQFP
(ST-48)
–22–
REV. 0