The AP494 incorporates on a single monolithic chip
all the functions required in the construction of a
pulse-width-modulation control circuit. Designed
primarily for power supply control, this device offers
the systems engineer the flexibility to tailor the
power supply control circuitry to a specific
application.
The AP494 contains two error amplifiers, one
adjustable on-chip oscillator, a dead-time control
(DTC) comparator, a pulse-steering control flip-flop,
a 5-V, 3%-precision regulator, and output-control
circuits.
The error amplifiers exhibit a common-mode
voltage range from –0.3V to V
CC
–2V. The
dead-time control comparator has a fixed offset that
provides approximately 5% dead time. The
on-chipped oscillator may be bypassed in two ways.
One is to terminate RT to the reference output
and the other one is to provide a sawtooth input to
CT, or it may drive the common circuits in
synchronous multiple-rail power supplies.
The uncommitted output transistors provide either
common-emitter
or
emitter-follower
output
capability. The AP494 provides for push-pull or
single-ended output operation, which may 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 AP494 is characterized for operation from 0
o
C
to 70
o
C.
Connection Diagram
(TOP VIEW)
1 IN+
1 IN-
FEEDBACK
DTC
CT
RT
GND
C1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
2 IN+
2 IN-
REF
OUTPUT CTRL
Vcc
C2
E2
E1
Ordering Information
AP494 X X X X
Temp. grade
Blank: 0 ~70
o
C
I : -40 ~85
o
C
Package
S16 : SOP-16L
N16 : DIP-16L
Lead Free
Blank : Normal
L : Lead Free Package
Packing
Blank : Tube
A : Taping
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev.1.0 Oct 11, 2004
1/9
AP494
Voltage Mode PWM Controller
Functional Block Diagram
RT 6
CT 5
4
~0.1V
~
OUTPUT CTRL
(see Function Table)
Oscillator
Dead-Time Control
Comparator
1D
C1
Error Amplifier 1
+
-
Error Amplifier 2
+
-
PWM
Comparator
Pulse-Steering
Flip-Flop
13
Q1
8
9
C1
E1
DTC
Q2 11 C2
10
12
E2
Vcc
1
1 IN +
2
1 IN -
2 IN + 16
2 IN - 15
Reference
Regulator
14
REF
7
FEEDBACK
3
0.7mA
GND
Absolute Maximum Ratings
Rating
Power Supply Voltage
Collector Output Voltage
Collector Output Current (Each transistor)
Amplifier Input Voltage Range
Power Dissipation @ T
A
≦45
o
C
Thermal Resistance, Junction-to-Ambient
Operating Junction Temperature
Storage Temperature Range
Operating Ambient Temperature Range
Derating Ambient Temperature
Symbol
V
CC
V
C1
, V
C2
I
C1
, I
C2
V
IR
P
D
R
Θ
JA
T
J
Tstg
T
A
T
A
Value
40
40
250
-0.3 to +40
1000
80
125
-55 to +125
0 to +70
45
Unit
V
V
mA
V
mW
o
C/W
o
C
o
C
o
C
o
C
Recommended Operating Conditions
Characteristics
Power Supply Voltage
Collector Output Voltage
Collector Output Current (Each transistor)
Amplified Input Voltage
Current Into Feedback Terminal
Reference Output Current
Timing Resistor
Timing Capacitor
Oscillator Frequency
Symbol
Min
V
CC
7.0
V
C1
,V
C2
-
I
C1
,I
C2
-
V
in
-0.3
I
fb
-
I
ref
-
R
T
1.8
C
T
0.0047
f
OSC
1.0
Typ
15
30
-
-
-
-
30
0.001
40
Max
40
40
200
V
CC
-2.0
0.3
10
500
10
200
Unit
V
V
mA
V
mA
mA
kΩ
µF
kHz
Anachip Corp.
www.anachip.com.tw
2/9
Rev.1.0 Oct 11, 2004
AP494
Voltage Mode PWM Controller
Electrical Characteristics
Characteristics
REFERENCE SECTION
Reference Voltage (I
O
=1.0mA)
Line Regulation (V
CC
=7.0 V to 40V)
Load Regulation (I
O
=1.0mA to 20mA)
Short Circuit Output Current (I
ref
=0 V)
OUTPUT SECTION
Collector Off-State Current (V
CC
=40V, V
CE
=40V)
Emitter Off-State Current (V
CC
=40V, V
C
=40V, V
E
=0V)
Collector-Emitter Saturation Voltage (Note 1)
Common-Emitter (V
E
=0V, I
C
=200mA)
Emitter-Follower (V
C
=15V, I
E
=-200mA)
Output Control Pin Current
Low State (V
OC
≤0.4V)
High State (V
OC
=V
ref
)
Output Voltage Rise Time
Common-Emitter (See Figure 4)
Emitter-Follower (See Figure 5)
Output Voltage Fall Time
Common-Emitter (See Figure 4)
Emitter-Follower (See Figure 5)
ERROR AMPLIFIER SECTION
Input Offset Voltage (V
O (Pin 3)
=2.5V)
Input Offset Current (V
O (Pin 3)
=2.5V)
Input Bias Current (V
O (Pin 3)
=2.5V)
Input Common Mode Voltage Range (V
CC
=40V, T
A
=25
o
C)
Open Loop Voltage Gain (ΔV
O
=3.0V, V
O
=0.5V to 3.5V, R
L
=2.0 k
Ω)
Unity-Gain Crossover Frequency (V
O
=0.5V to 3.5V, R
L
=2.0 kΩ)
Common Mode Rejection Ratio (VCC=40V)
Output Sink Current (V
O (Pin 3)
=0.7V)
Output Source Current (V
O (Pin 3)
=3.5V)
PWM COMPARATOR SECTION
(Test Circuit Figure 1)
Input Threshold Voltage (Zero Duty Cycle)
Input Sink Current (V
(Pin 3)
=0.7V)
DEADTIME CONTROL SECTION
(Test Circuit Figure 1)
Input Bias Current (Pin 4)(V
Pin4
=0V to 5.25V)
Maximum Duty Cycle, Each Output, Push-Pull Mode
(V
Pin4
=0V, C
T
=0.01µF, R
T
=12 kΩ)
Input Threshold Voltage (Pin4)
(Zero Duty Cycle)
(Maximum Duty Cycle)
(V
CC
=15V, C
T
=0.01µF, R
T
=12 KΩ, unless otherwise noted.) For typical values T
A
=25 C, for min/max values T
A
is the operating ambient
temperature range that applies, unless otherwise noted)
o
Symbol
V
ref
Reg
line
Reg
load
I
SC
I
C(off)
I
E(off)
V
sat(C)
V
sat(E)
I
OCL
I
OCH
t
r
t
f
Min
4.85
-
-
4.5
-
-
-
-
-
-
-
-
-
-
Typ
5.0
2.0
3.0
60
2.0
-
1.1
1.5
10
0.2
100
100
25
40
Max
5.15
25
15
75
100
-100
1.5
2.5
-
3.5
200
200
100
100
Unit
V
mV
mV
mA
µA
µA
V
µA
mA
ns
ns
NOTE:
1. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as
possible.
V
IO
I
IO
I
IB
V
ICR
A
VOL
f
C
CMRR
I
O-
I
O+
V
TH
I
I-
I
IB(DT)
DC
max
V
th
-
-
-
2.0
10
5.0
250
-0.1
-0.1
-0.3 to V
CC
-2.0
95
350
90
0.7
-15
4
0.7
-2.0
48
2.8
-
-
-
-
-
-
4.5
-
-10
50
mV
nA
µA
V
dB
kHz
dB
mA
mA
V
mA
µA
%
V
70
-
64
0.3
-10
-
0.3
-
45
-
0
3.3
-
Anachip Corp.
www.anachip.com.tw
3/9
Rev.1.0 Oct 11, 2004
AP494
Voltage Mode PWM Controller
Electrical Characteristics(Continued)
Characteristics
(V
CC
=15V, C
T
=0.01µF, R
T
=12 KΩ, unless otherwise noted.) For typical values T
A
=25 C, for min/max values T
A
is the operating ambient
temperature range that applies, unless otherwise noted)
o
Symbol
Min
Typ
Max
Unit
OSCILLATOR SECTION
Frequency (C
T
=0.01µF,RT=12 kΩ)
f
OSC
-
10
-
kHz
Standard Deviation of Frequency* (C
T
=0.001µF, R
T
=30 kΩ)
σf
OSC
-
3.0 -
%
o
Δf
OSC
(ΔV) -
0.1 -
%
Frequency Change with Voltage (V
CC
=7.0V to 40V, T
A
=25 C)
Frequency Change with Temperature (ΔT
A
=T
low
to T
high
)
Δf
OSC
(ΔT) -
-
12
%
(C
T
=0.01µF, R
T
=12 kΩ)
TOTAL DEVICE
Standby Supply Current(Pin6 at V
ref
, All other inputs and outputs
mA
I
CC
open)
5.5 10
-
(V
CC
=15V)
7.0 15
-
(V
CC
=40V)
Average Supply Current
mA
(C
T
=0.01µF, R
T
=12 kΩ, V
(Pin4)
=2.0V)
-
7.0 -
(V
CC
=15V) (See Figure 4)
*Standard deviation is a measure of the statistical distribution about the mean as derived from the formula,
