XRD9827
10
Rev. 3.00
ELECTRICAL CHARACTERISTICS (CONT'D)
Test Conditions: AV
DD
=DV
DD
= 3V, ADCCLK=6MHz, 50% Duty Cycle, T
A
=25°C unless otherwise specified.
Symbol Parameter Min. Typ. Max. Unit Conditions
System Specifications (MUX + Buffer + PGA + ADC) Note 1
SYS
DNL
System DNL -1.0 ±0.5 +6.0 LSB AV
DD
= DV
DD
= 3.0V
SYS
LIN
System Linearity ±6.0 LSB
SYS
GE
System Gain Error -5.0 +5.0 %
IRN Input Referred Noise 1.5 mV
rms
Gain=1
Input Referred Noise 0.5 mV
rms
Gain=10
System Timing Specifications
tcklw ADCCLK Low Pulse Width 50 83 ns
tckhw ADCCLK High Pulse Width 70 83 ns
tckpd ADCCLK Period 120 166 ns
tsypw SYNCH Pulse Width 30 ns
trars Rising ADCCLK to rising 0 SYNCH must rise equal to
SYNCH or after ADCCLK, See Figure 18
tclpw CLAMP Pulse Width 30 ns Note 2
Write Timing Specifications
tsclkw SCLK Pulse Width 40 ns
tdz LD Low to SCLK High 20 ns
tds Input Data Set-up Time 20 ns
tdh Input Data Hold Time 0 ns
tdl SCLK High to LD High 50 ns
ADC Digital Output Specifications
tap Aperture Delay 15 ns
tdv Output Data Valid 30 50 ns
tsa SYNCH to ADCCLK 20 ns 3ch Pixel Md
tlat Latency 8 cycles Config 00, 11
tlat Latency 6 pixels Config 01, 10
Digital Input Specifications
V
IH
Input High Voltage AV
DD
-0.5 V
V
IL
Input Low Voltage 1 V
I
IH
High Voltage Input Current 5 µA
I
IL
Low Voltage Input Current 5 µA
C
IN
Input Capacitance 10 pF
Note 1: System performance is specified for typical digital system timing specifications.
Note 2: The actual minimum ‘tclpw’ is dependent on the external capacitor value, the CIS output impedance.
During ‘clamp’ operation, sufficient time needs to be allowed for the external capacitor to charge up to the
correct operating level. Refer to the description in Theory of Operation, CIS Config.
XRD9827
11
Rev. 3.00
ELECTRICAL CHARACTERISTICS (CONT'D)
Test Conditions: AV
DD
=DV
DD
=3V, ADCCLK=6MHz, 50% Duty Cycle, T
A
=25°C unless otherwise specified.
Symbol Parameter Min. Typ. Max. Unit Conditions
Digital Output Specifications
V
OH
Output High Voltage 80
(
%) DVDD
I
L
= 1mA
V
OL
Output Low Voltage 20
(
%) DVDD
I
L
= -1mA
I
Oz
Output High-Z Leakage Current -10 10 µA
C
OUT
Output Capacitance 10 pF
SR Slew Rate (10% to 90% DV
DD
) 2 15 ns C
L
= 10pF, DV
DD
= 3.3V
XRD9827
12
Rev. 3.00
THEORY OF OPERATION
CIS Configuration (Contact Image Sensor)
The XRD9827 has two configurations for CIS applications. Each configuration is set by the control registers
accessed through the serial port.
Mode 1. DC Coupled
If the CIS does not have leading or trailing black pixels as shown in Figure 2, then DC couple the CIS output to the
XRD9827 input.
Optically Shielded
Pixels
Valid Pixels
Adjust the offset of the CIS (-100 mV to 500 mV) by setting the internal registers of the XRD9827 to set the black
pixel value when the LEDs of the CIS are off. When the LEDs are on, use the XRD9827 Programmable Gain to
maximize the ADCs dynamic range. Figure 3 shows a typical application for a CIS with an offset of -100mV to 500mV.
Figure 2. Typical Output CIS Mode

XRD9827ACU

Mfr. #:
Manufacturer:
MaxLinear
Description:
IC AFE 3 CHAN 12BIT 20SSOP
Lifecycle:
New from this manufacturer.
Delivery:
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