Intersil Corporation CA3224E Datasheet
CA3224E
November 1996
Features
• Automatic Picture Tube Bias Cutoff Control
• Automatic Background Color Balance
• Eliminates Grey Scale Adjustments
• Compensates for Cathode-to-Heater Leakage
• Electrostatic Protection on All Pins
• Servo Loop Design
• Wide Dynamic Range
• Three-Gun Control
• Minimal External Components
Ordering Information
TEMP.
PART NUMBER
CA3224E -40 to 85 22 Ld PDIP E22.4
RANGE (oC) PACKAGE
Pinout
Automatic Picture Tube Bias Control Circuit
Description
The CA3224E is an automatic picture tube bias control circuit used in color TV receiver CRT drive circuits. It is used to
provide dynamic bias control of the grey scale both initially
and over the CRT operating life, compensating for CRT cutoff changes.
The CA3224E provides automatic continuous control of the
cutoff current in each gun of a three-gun color CRT. From an
input pulse amplitude proportional to the difference between
the desired and the actual CRT cutoff, a gated sample/hold
circuit generates a DC correction voltage which correctly
biases the CRT driver circuit. The sample/hold bias correction takes place each frame following the vertical blanking.
Figure 1 shows a block diagram of the CA3224E. The functions include three identical servo loop transconductance
PKG.
NO.
amplifiers with a sample/hold switch and buff er amplifier plus
control logic, internal bias and a mode switch.
GROUND
CHANNEL 1 INPUT
CHANNEL 1 FREQ COMPENSATION
CHANNEL 2 INPUT
CHANNEL 2 FREQ COMPENSATION
CHANNEL 3 INPUT
CHANNEL 3 FREQ COMPENSATION
VERTICAL INPUT
GROUND
HORIZONTAL INPUT
GRID PULSE OUTPUT
1
2
3
4
5
6
7
8
9
10
11
CA3224E
(PDIP)
TOP VIEW
V
22
CC
CHANNEL 1 HOLD CAP
21
CHANNEL 1 OUTPUT
20
CHANNEL 2 HOLD CAP
19
CHANNEL 2 OUTPUT
18
CHANNEL 3 HOLD CAP
17
CHANNEL 3 OUTPUT
16
V
15
14
13
12
BYPASS
REF
AUTO BIAS LEVEL ADJUST
AUTO BIAS PULSE OUTPUT
PROGRAM PULSE OUTPUT
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Copyright © Intersil Corporation 1999
8-56
File Number 1553.1
CA3224E
Absolute Maximum Ratings T
Supply Voltage (VCC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-1 to V
Output Current . . . . . . . . . . . . . . . . . . . . . . . Short Circuit Protected
=25oC Thermal Information
A
Thermal Resistance (Typical, Note 1) θJA (oC/W)
CC
PDIP Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Maximum Junction Temperature (Plastic Package) . . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC
Operating Conditions
Maximum Lead Temperature (Soldering 10s). . . . . . . . . . . . . 300oC
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
Supply Voltage Range (Typical) . . . . . . . . . . . . . . . . . . . . 10V ±10%
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications At T
= 25oC, VCC = 10V, V
A
= 3.75V, VV(Pin 8) = VH (Pin 10) = 6.0V, S1 = A, S2 = A,
BIAS
See Test Circuit and Timing Diagrams
PARAMETER TEST PIN NO. SYMBOL TEST CONDITIONS MIN TYP MAX UNITS
Supply Current 22 I
Reference Voltage 2, 4, 6 V
Input Current 2, 4, 6 I
Output Current Source 17,19, 21 lOM+V
Sink lOM-V
Output Buffer Input Current 17,19, 21 I
CC
Measure at t
REF
VIN = 7.2V, S1 = B - - 250 nA
I
BIAS
BIAS
V
I
OUT
4
= 0.5V, Measure at t6, S1 = B - - -0.8 mA
= 7.0V, Measure at t6, S1 = B 0.8 - - mA
= 6.5V, V
IN
- - 65 mA
5.6 6.0 6.4 V
- - 150 nA
At pins 16, 18, 20,
Voltage Gain A
Measure at t4, S1 = B
V
0.97 - 1.07 -
Transconductance 17,19, 21 g
Measure at t6, VIN = 8mV
M
P-P
50 - 100 mS
at 40kHz, S1 = B
Auto Bias Pulse Output Low 13 V
High V
OL
OH
Measure at t
Measure at t
1
4
- - 0.3 V
6.05 - - V
Current Sink lOM- Measure at t4, S2 = B 2.5 - - mA
Grid Pulse Output Low 11 V
High V
Program Pulse Output Low 12 V
High V
Vertical Input 8 V
Horizontal Input 10 V
Measure at t
OL
Measure at t
OH
Measure at t
OL
Measure at t
OH
See Figure 3 - 6.0 - V
V
See Figure 3 - 6.0 - V
H
4
1
6
1
- - 0.4 V
4.2 - - V
- - 0.4 V
8.2 - - V
Auto Bias Pulse Timing Start 13 t0 to t2, Note 2 835 - 842 µs
Finish t0to t7, Note 2 1270 - 1275 µs
Grid Pulse Timing Start 11 t0 to t3, Note 2 899 - 905 µs
Finish t0 to t5, Note 2 1080 - 1084 µs
Program Pulse Timing Start 12 t0 to t5, Note 2 1080 - 1084 µs
Finish t0 to t7, Note 2 1270 - 1275 µs
NOTE:
2. All time measurements are made from 50% point to 50% point.
8-57
Loading...