SONY CXA3791EN

High-speed Buffer Amplifier for CCD Image Sensor
CXA3791EN
Description
The CXA3791EN is a high-speed buffer amplifier IC.
(Applications: CCD image sensor output buffers, Digital still cameras, Camcorders, Other general buffers)
Features
‹ Power consumption: 22mW (typ.)
(IDRV = 50μA (180kΩ when VCC = 13V), ISF pin connected to GND, during no signal)
‹ Push-pull output
‹ High-speed response: 500V/μs (IDRV = 50μA (180kΩ when VCC = 13V), CL = 20pF)
‹ Internal sink current mode for CCD with open source output
(Settable by external resistance RISF)
‹ Enables to set the responsibility by changing the drive current by an external resistor
Structure
Bipolar silicon monolithic IC
Absolute Maximum Ratings
(Ta = 25°C)
Š Supply voltage
VCC
Š Supply voltage
IN
Š Storage temperature
Tstg
Š Allowable power dissipation
PD
16
V
GND – 0.3 to VCC + 0.3
V
–65 to +150
°C
0.22
W
(when mounted on a two-layer board; 13mm × 13mm, t = 0.63mm)
Recommended Operating Conditions
Š Supply voltage
VCC
9.0 to 15.5
V
Š Operating temperature
Ta
–20 to +75
°C
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license
by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating
the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
-1-
E08233-PS
CXA3791EN
Block Diagram and Pin Configuration
(Top View)
ISF
VCC
IDRV
6
5
4
1
2
3
IN
GND
OUT
Pin Description and I/O Pin Equivalent Circuit
Pin
No.
2
5
Symbol
I/O
GND
VCC
—
—
Standard
voltage level
0V
13V
Equivalent circuit
—
—
Description
GND.
Supply voltage input.
VCC
10 ×
IDRV
2k
1
IN
I
CCD
output voltage
1
Input.
58 ×
IISF
2k
10 ×
IDRV
GND
External resistor connection for setting
the sink current for CCD with open
source output.
Connect an external resistor between
this pin and VCC (Pin 5).
Connect this pin to GND (Pin 2) when
not using this function.
* Set the resistance so that ISF current
is 90μA or less.
VCC
6
ISF
I
—
6
30k
20k
GND
VCC
50
3
OUT
O
≈IN
3
Output.
50
GND
VCC
4
IDRV
I
—
4
30k
20k
GND
-2-
External resistor connection for setting
the drive current.
Connect an external resistor between
this pin and VCC (Pin5).
* Set the resistance so that IDRV
current is 90μA or less.
CXA3791EN
Electrical Characteristics
(Ta = 25°C, VCC = 13V, RIDRV = 180kΩ, ISF pin: connected to GND)
DC Characteristics
Item
Supply current
Symbol
Measurement conditions
Min.
Typ.
Max.
Unit
ICC
IN = 10V, RIDRV = 180kΩ
1.4
1.6
1.8
mA
—
0.999
—
V/V
–100
—
100
mV
*1
IN: 10Vdc ΔV = 1V
GAIN = ΔOUT/ΔV
Voltage gain
VGAIN
I/O offset voltage
VOFFSET
IN = 10V
VOFFSET = OUT-IN
I/O voltage range
VRANGE
RIDRV = 78kΩ
RIDRV = 120kΩ
RIDRV = 180kΩ
RIDRV = 270kΩ
3.3
2.9
2.5
2.1
—
—
—
—
VCC – 2.0
VCC – 1.85
VCC – 1.8
VCC – 1.7
V
Input bias current
IBIAS
IN = 10V, ISF = 0V
–15
–5
6
μA
Sync current
ISINK
IN = 10V, RISF = 180kΩ
2.6
2.9
3.2
mA
*1
Voltage gain
10.5V
IN
ΔV = 1V
9.5V
OUT
ΔOUT
-3-
CXA3791EN
AC Characteristics
(Ta = 25°C, VCC = 13V, IDRV = 50μA (180kΩ when VCC = 13V), ISF pin: connected to GND, RL = 15Ω, CL = 20pF)
Item
Symbol
Measurement conditions
Bandwidth
GBW
IN = 50mVp-p
Rise time
TRISE
IN = 9.5 to 10.5V
10 to 90%
Fall time
TFALL
IN = 10.5 to 9.5V
10 to 90%
I/O delay time
TDELAY
IN = 9.5 to 10.5V
@50%
Min.
Typ.
Max.
Unit
—
220
—
MHz
—
2.5
3.5
ns
—
3.0
4.0
ns
0.9
1.0
2.0
ns
*1
*1
*1
*1
Rise time, fall time and I/O delay time
10.5V
50%
IN
9.5V
90%
90%
OUT
50%
10%
TFALL
10%
TRISE
TDELAY
-4-
CXA3791EN
Evaluation Circuit
180kΩ
180kΩ
1000pF
47µF
VCC
ISF
6
IDRV
4
5
1
3
2
IN
GND
15Ω
OUT
20pF
A
13V
GND
-5-
CXA3791EN
Description of Operation
Current Settings
1. Output Drive Current
The small signal output impedance of the OUT pin (Pin 3) can be set by connecting the IDRV pin (Pin 4) to VCC
through a resistor. The inflow current to the IDRV pin is multiplied by 10 times inside the IC, and flows as the
output stage idling current.
The IDRV pin has an internal 50kΩ resistor, so the inflow current to the IDRV pin can be calculated as follows.
IIDRV = (VCC – VBE × 2)/(RIDRV + 50kΩ)
= (13 – 1.46)/(180kΩ + 50kΩ)
= 50.2μA
Here, VCC = 13V, VBE = 0.73V (typ.), and RIDRV = 180kΩ.
The small signal output impedance at this time can be calculated as follows.
ROUT = (26mV/(10 × IIDRV))/2
= (26mV/502μA)/2
= 26Ω
2. Sink Current for CCD with open source output
The sink current of the IN pin (Pin 6) can be set by connecting the ISF pin (Pin 1) to VCC through a resistor.
This sink current can be used as the CCD output stage source follower drive current. The inflow current to the
ISF pin is multiplied by 58 times inside the IC, and flows as the sink current.
The ISF pin has an internal 50kΩ resistor, so the inflow current to the ISF pin can be calculated as follows.
IISF = (VCC – VBE × 2)/(RISF + 50kΩ)
= (13 – 1.46)/(180kΩ + 50kΩ)
= 50.2μA
Here, VCC = 13V, VBE = 0.73V (typ.), and RISF = 180kΩ.
The sink current at this time can be calculated as follows.
Isink = 58 × IISF
= 2.9mA
Note) This IC operation depends on IDRV and ISF.
Set the external resistance so that IDRV and ISF current are 90μA or less, referring to the table shown
below.
[IDRV and ISF vs. external resistor]
Current (μA)
90
68
50
35
26
Unit
When VCC = 15V
100
150
220
330
470
kΩ
When VCC = 13V
78
120
180
270
390
kΩ
-6-
CXA3791EN
Example of Representative Characteristics
(Upper side) I/O voltage range vs.
IDRV pin setting resistance
(Lower side) I/O voltage range vs.
IDRV pin setting resistance
Vcc – 0.0
5.0
Ta = 25˚C
Ta = 25˚C
4.5
0.5
4.0
1.0
I/O voltage [V]
I/O voltage [V]
3.5
1.5
Vcc = 13V
Vcc = 15V
2.0
2.5
3.0
Vcc = 15V
2.5
Vcc = 13V
2.0
1.5
3.0
1.0
3.5
0.5
4.0
0.0
0
50
100
150
200
250
300
350
0
IDRV pin setting resistance [kΩ]
50
100
200
250
300
350
IDRV pin setting resistance [kΩ]
Current consumption vs. IDRV pin setting resistance
Sink current vs. ISF pin setting resistance
7.0
4.0
Ta = 25˚C
Ta = 25˚C
3.5
6.0
3.0
2.5
Sink current [mA]
Current consumption [mA]
150
Vcc = 15V
Vin = Vcc – 5V
2.0
Vcc = 13V
Vin = Vcc – 4V
1.5
5.0
4.0
Vcc = 15V
Vin = Vcc – 5V
3.0
Vcc = 13V
Vin = Vcc – 4V
2.0
1.0
1.0
0.5
0.0
0.0
0
50
100
150
200
250
300
0
350
50
100
150
200
250
300
350
IDRV pin setting resistance [kΩ]
ISF pin setting resistance [kΩ]
Current consumption vs. Supply voltage
Current consumption vs. Operating temperature
2.0
2.0
1.8
1.6
Current consumption [mA]
Current consumption [mA]
Ta = 25˚C
Ridrv = 180kΩ
Vin = Vcc – 4V
1.4
Ridrv = 220kΩ
Vin = Vcc – 5V
1.8
1.6
Vcc = 15V
Ridrv = 220kΩ
Vin = Vcc – 5V
Vcc = 13V
Ridrv = 180kΩ
Vin = Vcc – 4V
1.4
1.2
1.0
10.0
11.0
12.0
13.0
14.0
15.0
16.0
Supply voltage [V]
1.2
–50.0
–25.0
0.0
25.0
50.0
Operating temperature [˚C]
-7-
75.0
100.0
CXA3791EN
I/O offset voltage vs. Supply voltage
I/O offset voltage vs. Operating temperature
20.0
20.0
Ta = 25˚C
10.0
I/O offset voltage [mV]
I/O offset voltage [mV]
10.0
0.0
Ridrv = 220kΩ
Vin = Vcc – 5V
Ridrv = 180kΩ
Vin = Vcc – 4V
–10.0
–20.0
10.0
11.0
12.0
13.0
14.0
15.0
0.0
Vcc = 13V
Ridrv = 180kΩ
Vin = Vcc – 4V
Vcc = 15V
Ridrv = 220kΩ
Vin = Vcc – 5V
–10.0
–20.0
–50.0
16.0
–25.0
0.0
25.0
50.0
75.0
100.0
Operating temperature [˚C]
Supply voltage [V]
Input bias current vs. Supply voltage
Input bias current vs. Operating temperature
5.0
3.4
Ta = 25˚C
Input bias current [µA]
Input bias current [µA]
3.2
0.0
Ridrv = 220kΩ
Vin = Vcc – 5V
–5.0
Ridrv = 180kΩ
Vin = Vcc – 4V
–10.0
3.0
Vcc = 15V
Ridrv = 220kΩ
Vin = Vcc – 5V
2.8
Vcc = 13V
Ridrv = 180kΩ
Vin = Vcc – 4V
2.6
–15.0
10.0
11.0
12.0
13.0
14.0
15.0
2.4
–50.0
16.0
–25.0
0.0
25.0
50.0
75.0
100.0
Operating temperature [˚C]
Supply voltage [V]
Sink current vs. Supply voltage
Sink current vs. Operating temperature
3.4
4.0
Ta = 25˚C
3.2
Ridrv/Risf = 180kΩ
Vin = Vcc – 4V
Sink current [mA]
Sink current [mA]
3.5
3.0
2.5
Ridrv/Risf = 220kΩ
Vin = Vcc – 5V
11.0
12.0
13.0
14.0
15.0
16.0
Vcc = 15V
Ridrv/Risf = 220kΩ
Vin = Vcc – 5V
2.8
2.6
2.0
1.5
10.0
3.0
2.4
–50.0
Vcc = 13V
Ridrv/Risf = 180kΩ
Vin = Vcc – 4V
–25.0
0.0
25.0
50.0
Operating temperature [˚C]
Supply voltage [V]
-8-
75.0
100.0
CXA3791EN
Tr and Tf vs. Supply voltage
Tr and Tf vs. Operating temperature
6.0
4.0
3.5
5.0
Tf
3.0
Tr
Tf
Tr and Tf [ns]
Tr and Tf [ns]
4.0
Tr
3.0
2.0
Ta = 25˚C, Idrv = 50µA,
CL = 20pF, RL = 15Ω,
Input DC offset = VCC – 5V,
Input amplitude = 1.0V,
Input rise, fall time = 2.0ns
1.0
0
10.0
11.0
12.0
13.0
14.0
2.5
2.0
1.5
Idrv = 50µA,
CL = 20pF, RL = 15Ω,
Input DC offset = VCC – 5V,
Input amplitude = 1.0V,
Input rise, fall time = 2.0ns
1.0
0.5
15.0
0
–50
16.0
1.75
1.50
1.50
I/O delay time [ns]
1.75
1.25
1.00
0.75
Ta = 25˚C, Idrv = 50µA,
CL = 20pF, RL = 15Ω,
Input DC offset = VCC – 5V,
Input amplitude = 1.0V,
Input rise, fall time = 2.0ns
12.0
11.0
13.0
14.0
75
100
Idrv = 50µA,
CL = 20pF, RL = 15Ω,
Input DC offset = VCC – 5V,
Input amplitude = 1.0V,
Input rise, fall time = 2.0ns
1.25
1.00
0.75
0.50
0.25
15.0
16.0
0
–50
0
–25
25
50
75
Supply voltage [V]
Operating temperature [˚C]
Positive pulse response
Negative pulse response
0.2V/div
0
10.0
50
I/O delay time vs. Operating temperature
2.00
0.2V/div
I/O delay time [ns]
I/O delay time vs. Supply voltage
2.00
0.25
25
Operating temperature [˚C]
Supply voltage [V]
0.50
0
–25
Idrv = 50µA, CL = 20pF, RL = 15Ω
Input rise, fall time = 2.0ns
T
Input
100
Output
T
10.0V
10.0V
T Output
T
Input
Idrv = 50µA, CL = 20pF, RL = 15Ω
Input rise, fall time = 2.0ns
Ch1 200mVΩ Ch2 200mVΩ M 1.00ns Ch1
10.0V
1.0ns/div
-9-
Ch1 200mVΩ Ch2 200mVΩ M 1.00ns Ch1
10.0V
1.0ns/div
CXA3791EN
Application Circuit 1 when using CCD with open source output
180kΩ
180kΩ
1000pF
0.1µF
0.1µF
VCC
ISF
6
IDRV
4
5
1
3
2
IN
GND
OUT
13V
GND
CDS/ADC
CCD
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
- 10 -
CXA3791EN
Application Circuit 2 when using CCD with internal current source
180kΩ
1000pF
VCC
ISF
6
IDRV
4
5
1
3
2
IN
0.1µF
GND
OUT
13V
GND
CDS/ADC
CCD
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
- 11 -
CXA3791EN
Notes on Operation
‹ Provide the widest GND pattern possible on the board.
‹ Use a 1000pF (recommended) and a 0.1μF (recommended) ceramic capacitors in parallel for the bypass
capacitor connected between the power supply and GND, and connect them as close to the IC pins as
possible.
‹ Load capacitance causes the input/output wiring response to worsen and results in noise. Use the shortest
wiring layout possible, and shield it with GND.
‹ When the output pin (Pin 3) is shorted to either the power supply or GND, an overcurrent may flow to the
output stage elements and damage them.
When the input pin (Pin 1) is shorted to GND, an overcurrent may flow to the internal parasitic elements and
damage them.
- 12 -
CXA3791EN
Package Outline
(Unit: mm)
LEAD PLATING SPECIFICATIONS
ITEM
- 13 -
SPEC.
LEAD MATERIAL
COPPER ALLOY
SOLDER COMPOSITION
Sn-Bi Bi:1-4wt%
PLATING THICKNESS
5-18µm
Sony Corporation