AZ494P [ETC]
PULSE-WIDTH-MODULATION CONTROL CIRCUITS; 脉宽调制控制电路
| 型号： | AZ494P |
| 厂家： | 
ETC |
| 描述： | PULSE-WIDTH-MODULATION CONTROL CIRCUITS |
| 文件： | 总12页 (文件大小：274K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
AZ494
General Description
Features
The AZ494 incorporates on a single chip all the func-
tions required in the construction of a pulse-width-
modulation (PWM) control circuit. Designed primarily
for power supply control, this device offers the flexibil-
ity to tailor the power supply control circuitry to a spe-
cific application.
·
·
Complete PWM power-control circuitry
Uncommitted outputs for 200mA sink or source
current
·
·
·
·
·
Output control selects single-ended or push-pull
operation
Internal circuitry prohibits double pulse at either
output
The AZ494 contains two error amplifiers, an on-chip
adjustable oscillator, a dead-time control (DTC) com-
parator, a pulse-steering control flip-flop, a 5V regula-
tor, and output control circuits. The error amplifiers
exhibit a common-mode voltage range from -0.3V to
Variable dead time provides control over total
range
Internal regulator provides a stable 5V reference
supply with 5% tolerance
Circuit architecture allows easy synchronization
V
-2V. The dead-time control comparator has a fixed
CC
offset that provides approximately 5% dead time. The
on-chip oscillator can be bypassed by terminating the
RT pin to the reference output and providing a saw-
tooth input to the CT pin, or it can drive the common
circuits in synchronous multiple-rail power supplies.
Applications
·
·
SMPS
Back Light Inverter
The uncommitted output transistors can be configured
in either common-emitter or emitter-follower output
topology. The AZ494 provides for push-pull or single-
ended output operation, which can be selected through
the output control function. The architecture of this
device prohibits the possibility of either output being
pulsed twice during push-pull operation. The AZ494 is
o
o
characterized for operation from -40 C to 85 C.
DIP-16
SOIC-16
Figure 1. Package Types of AZ494
March. 2003
Rev.1.0
1
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
AZ494
Pin Configuration
M Package / P Package
(SOIC-16 / DIP-16)
1IN +
1
16
2IN +
2IN -
1IN -
2
15
FEEDBACK
DTC
3
4
5
6
7
8
14
13
12
11
10
9
REF
OUTPUT CTRL
CT
V
CC
RT
C2
E2
E1
GND
C1
Top View
Figure 2. Pin Configuration of AZ494
Function Table
Input To Output Control
Output Function
VI = GND
VI = Vref
Single-ended or parallel output
Normal push-pull operation
Functional Block Diagram
Output CTRL
see Function Table
6
5
13
8
RT
CT
C1
Oscillator
Pulse-Steering
Flip-Flop
Q1
Dead-Time Control
Comparator
9
E1
D
C2
11
4
DTC
CK
Q2
0.12V
Error Amplifier 1
10
E2
PWM
Comparator
1
2
1IN +
1IN -
12
VCC
Error Amplifier 2
16
15
Reference
Regulator
14
2IN +
2IN -
REF
0.7mA
7
GND
3
FEEDBACK
Figure 3. Functional Block Diagram of AZ494
March. 2003
Rev.1.0
2
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Ordering Information
AZ494
Package
SOIC-16
DIP-16
Temperature Range
Part Number
AZ494M
AZ494P
Marking ID
AZ494M
AZ494P
Packing Type
-40oC~85oC
Tube
Tube
Absolute Maximum Ratings (Note 1)
Parameter
Symbol
Value
Unit
Supply Voltage (Note 2)
VCC
VI
40
V
V
Amplifier Input Voltage
Collector Output Voltage
Collector Output Current
-0.3 to VCC + 0.3
VO
IO
40
V
250
mA
oC/W
Package Thermal Impedance
(Note 3)
M Package
P Package
73
67
θ
JA
oC
Lead Temperature 1.6mm from case for 10 seconds
Storage Temperature Range
260
-65 to 150
200
oC
V
TSTG
ESD rating (Machine Model)
Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the
device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those indicated under "Recommended Operation Ratings" is not implied. Exposure to "Absolute Maximum Rat-
ings"for extended periods may affect device reliability.
Note 2: All voltage values are with respect to the network ground terminal.
Note 3: Maximum power dissipation is a function of T (max), θ and T . The maximum allowable power dissipa-
J
JA
A
tion at any allowable ambient temperature is P = ( T (max) - T ) / θ . Operating at the absolute maximum T of
D
J
A
JA
J
o
150 C can affect reliability.
March. 2003
Rev.1.0
3
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Recommended Operating Conditions
AZ494
Parameter
Symbol
Min
Max
Unit
Supply Voltage
VCC
7
36
V
Amplifier Input Voltage
Collector Output Voltage
VI
-0.3
VCC - 2
36
V
V
VO
Collector Output Current
(Each Transistor)
200
mA
Current Into Feedback Terminal
Oscillator Frequency
0.3
300
mA
KHz
fosc
CT
RT
TA
Timing Capacitor
0.47
1.8
10000
500
nF
Timing Resistor
KΩ
oC
Operating Free-Air Temperature
-40
85
March. 2003
Rev.1.0
4
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Electrical Characteristics
AZ494
o
All typical values, except for parameter changes with temperature, are at T = 25 C.
A
Vcc=15V, f=10KHz unless otherwise noted.
Parameter
Symbol
Conditions (Note 4)
Min Typ Max
Unit
Reference Section
Output Voltage (REF)
Vref
IO=1mA
4.75
5
2
5.25
25
V
mV
Line Regulation
VCC = 7V to 36V
IO=1mA to 10mA
∆TA = MIN to MAX
REF = 0V
Load Regulation
1
15
mV
Output Voltage Change with Temperature
Short-Circuit Output Current (Note 5)
2
10
mV/V
mA
ISC
25
Oscillator Section, CT = 0.01µF, RT = 12KΩ (See Figure 4)
Frequency
fosc
10
KHz
Standard Deviation of Frequency
(Note 6)
All values of VCC, CT, RT and
TA constant
100
Hz/KHz
VCC=7V to 36V, TA = 25oC
Frequency Change with Voltage
1
Hz/KHz
Hz/KHz
Frequency Change with Temperature
(Note 7)
∆TA= MIN to MAX
10
Error-Amplifier Section (See Figure 5)
Input Offset Voltage
VOS
IOS
VO (FEEDBACK) = 2.5V
VO (FEEDBACK) = 2.5V
2
10
250
1
mV
nA
µA
V
Input Offset Current
25
0.2
Input Bias Current
IBIAS VO (FEEDBACK) = 2.5V
VCC=7V to 36V
Common-Mode Input Voltage Range
-0.3 to
VCC-2
Large-Signal Open-Loop Voltage Gain
AVO
∆VO = 3V, RL =2KΩ,
VO =0.5V to 3.5V
70
95
dB
Large-Signal Unity-Gain Bandwidth
Common-Mode Rejection Ratio
GB
VO =0.5V to 3.5V, RL =2KΩ
∆VO = 36V, TA = 25oC
800
80
KHz
dB
CMRR
65
Output Sink Current (FEEDBACK)
ISINK
VID = -15mV to -5V,
V(FEEDBACK) = 0.7V
0.3
0.7
mA
Output Source Current (FEEDBACK)
ISOURCE VID = 15mV to 5V, V(FEED-
BACK) = 3.5V
-2
mA
Output Section
Collector Off-State Current
IC, OFF VCE = 36V, VCC=36V
IE, OFF VCC = VC = 36V, VE = 0
VE = 0, IC =200mA
2
100
-100
1.3
µA
µA
V
Emitter Off-State Current
Collector-Emitter
Saturation Voltage
Common
Emitter
Emitter Fol-
lower
1.1
1.5
VO (C1 or C2) = 15V,
IE = -200mA
2.5
March. 2003
Rev.1.0
5
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Electrical Characteristics (Continued)
AZ494
Parameter
Symbol Conditions
Min
Typ Max
Unit
Output Control Input Current
VI = Vref
3.5
mA
Dead-Time Control Section
Input Bias Current
VI = 0 to 5.25V
-2
-10
µA
Maximum Duty Cycle,
Each Output
VI (DEAD-TIME CTRL) = 0, CT
=0.01µF, RT =12KΩ
45
%
Input Threshold Voltage
Zero Duty Cycle
Maximum Duty Cycle
3
3.3
4.5
V
0
PWM Comparator Section (See Figure 4)
Input Threshold Voltage (FEEDBACK)
Input Sink Current (FEEDBACK)
Total Device
Zero duty cycle
V(FEEDBACK) = 0.7V
4
0.7
V
mA
0.3
Standby Supply Current
ISTDBY RT=Vref, All other VCC = 15V
6
9
10
15
mA
mA
inputs and outputs
open
VCC = 36V
Average Supply Current
VI (DEAD-TIME-CTRL) =2V
See Figure 4.
7.5
Switching Characteristics
Rise Time
tr
tf
tr
tf
Common-emitter Configuration
See Figure 6
100
25
200
100
200
100
ns
ns
ns
ns
Fall Time
Rise Time
Fall Time
Emitter-follower Configuration
See Figure 7
100
40
Note 4: For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating
conditions.
Note 5: Duration of the short circuit should not exceed one second.
Note 6: Standard deviation is a measure of the statistical distribution about the mean as derived from the formula:
Note 7: Temperature coefficient of timing capacitor and timing resistor are not taken into account.
March. 2003
Rev.1.0
6
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Parameter Measurement Information
VCC = 15V
AZ494
12
150Ω
150Ω
2W
2W
VCC
4
3
8
9
DTC
C1
E1
Output 1
Test
Inputs
FEEDBACK
12KΩ
6
11
10
RT
CT
C2
E2
Output 2
5
1
0.01uF
1IN+
1IN-
2
16
15
13
2IN+
2IN-
14
OUTPUT
CTRL
REF
GND
50KΩ
7
Test Circuit
VCC
0V
Voltage
at C1
VCC
0V
Voltage
at C2
Voltage
at CT
Threshold Voltage
DTC
0V
Threshold Voltage
FEEDBACK
0.7V
0%
MAX
0%
Duty Cycle
Voltage Waveforms
Figure 4. Operational Test Circuit and Waveforms
March. 2003
Rev.1.0
7
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Parameter Measurement Information
AZ494
Amplifier Under Test
VI
FEEDBACK
Vref
Other Amplifier
Figure 5. Error Amplifier Characteristics
15V
68Ω
2W
tf
tr
90%
Each Output
Circuit
Output
90%
CL = 15pF
(See Note A)
10%
10%
Note A: CL includes probe and jig capacitance.
Figure 6. Common-Emitter Configuration
15V
Each Output
Circuit
90%
90%
Output
10%
10%
tf
68Ω
2W
CL = 15pF
tr
(See Note A)
Note A: CL includes probe and jig capacitance.
Figure 7. Emitter-Follower Configuration
March. 2003
Rev.1.0
8
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Typical Characteristics
AZ494
100k
Vcc=15V
TA=25oC
0.001uF
10k
1k
0.01uF
0.1uF
CT=1uF
100
10
1k
10k
100k
1M
Timing Resistance-Ω
Figure 8. Oscillator Frequency vs. Timing Resistance
100
Vcc=15V
90
80
70
60
50
40
30
20
10
0
∆Vo=3V
TA=25oC
1
10
100
1k
10k
100k
1M
Frequency-Hz
Figure 9. Error Amplifier Small-Signal Voltage Gain vs. Frequency
March. 2003
Rev.1.0
9
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Mechanical Dimensions
AZ494
SOIC-16
1.65
1.30
0.70
0.406
A
20:1
B
0.55±0.05
°
±2°
3
1.27
φ2.0
Depth 0.06～
0.10
R0.20
R0.20
0.25(0.20min)
0.20±0.05
6.04
C-C
50:1
3.94
B
20:1
8°
C
C
0.20
Sφ1.00×0.20
5
°±2°
8°
0.40×45°
8°
A
March. 2003
Rev.1.0
10
Data Sheet
Advanced Analog Circuits
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
Mechanical Dimensions (Continued)
AZ494
DIP-16
7.62±0.25
5°
19.0±0.10
6°
6°
1.524
4°
4°
φ3×0.10±0.05
0.254
8.4～9.0
0.254
0.457
2.54
R0.75
March. 2003
Rev.1.0
11
Advanced Analog Circuits
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，
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IMPORTANT NOTICE
Advanced Analog Circuits Corporation reserves the right to make changes to its products or specifications at any time, without
notice, to improve design or performance and to supply the best possible product. Advanced Analog Circuits does not assume any
responsibility for use of any circuitry described other than the circuitry embodied in Advanced Analog Circuits' products. The
company makes no representation that circuitry described herein is free from patent infringement or other rights of Advanced Ana-
log Circuits Corporation.
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