AIC AIC1562CS High-efficiency, bootstrapped dc/dc converter Datasheet

AIC1562
High-Efficiency, Bootstrapped DC/DC Converter
FEATURES
DESCRIPTION
3V to 20V Input Voltage Operation.
The AIC1562 is a high performance monolithic
Internal 800mA Switch.
DC/DC
Bootstrapped Driver for N-Channel MOSFET.
bootstrapping capability, designed specifically for
High Efficiency (up to 90%).
driving N-channel MOSFET to achieve maximum
Fast Transient Response.
possible power conversion efficiency. The device
Internal ±2% Reference.
consists of an internal temperature compensated
Low Quiescent Current at 1.6mA.
reference,
Frequency Operation from 200Hz to 200KHz.
oscillator, bootstrapped driver and a 800mA output
converter
drive
comparator,
IC
with
controlled
output-
duty
cycle
switch. Working with the AIC1741, a low power
APPLICATIONS
adjustable regulator, the AIC1562 works at 100%
CPU Power Supplies for Mother Boards.
duty cycle under heavy load transient conditions to
DC/DC Converters for CPU VRMs.
minimize transient response time, making it an idea
Step-Down DC-DC Converter Module.
precision switching power solution to stringent
requirements on computer mother boards.
TYPICAL APPLICATION CIRCUIT
C3
+
AIC1562
TC
VCC
GND
FB
C1
47µF
R1
1K
Q2
C2
220pF
R8
10K
C11, C12: Ceramic Capacitor
L1: Iron Powder Core
VOUT= (1+R10/1K)x1.235V
C4
D1
VOUT : 2.5V~3.5V/10A
L1
+
Z1
5.1V
VIN
FB
GND
VOUT
AIC1741
5V
1000µF/6.3Vx2
C8, C9
7.5µF
0.022µF
R2
24K
+
1000µF
12V
SE
MTD20N03DH
Q1
SC
2N2907A
D3
BST
VIN
1N4148
BYV118
0.1µF
D2
1N4148
C10 C11 C12
0.1µF 0.1µF
1000µF/6.3V
x2
x2
x5
+
C13
P5
MICROPROCESSOR
CPU
R10
R8
R7 C5
470 0.1µF 1K
R9
1K
CPU Power Supply for P5 Mother Board
Analog Integrations Corporation
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
DS-1562-00
TEL: 886-3-5772500
Jan 30, 01
FAX: 886-3-5772510
www.analog.com.tw
1
AIC1562
ORDERING INFORMATION
AIC1562 XX
ORDER NUMBER
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
AIC1562CN
(PLASTIC DIP)
TEMPERATURE
C: 0°C~+70°C
AIC1562CS
(PLASTIC SO)
PIN CONFIGURATION
TOP VIEW
SC 1
8 BST
SE
2
7 NC
TC
3
GND 4
6 VCC
5 FB
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
...............................................…………………....................................... 20V
Comparator Input Voltage Range .........................…………….............................. -0.3V~20V
Switch Collector Voltage
Switch Emitter Voltage
....................................………………...................................... 20V
......................................…………………................................... 20V
Switch Collector to Emitter Voltage
Driver Collector Voltage
.......................……………..................................... 20V
.....................................………………..................................... 20V
Switch Current ...............................................................…...………………........…........... 1A
Power Dissipation and Thermal Characteristics
DIP Package
Ta= 25°C
................................…………........................... 1.0W
Thermal Resistance ..........………............................... 100°C/W
SO Package
Ta= 25°C ...........................……………......................... 625mW
Thermal Resistance ...............……….......................... 160°C/W
Operating Junction Temperature
.............................…………................................... 125°C
Operating Ambient Temperature Range
...................…………............................ 0°C~70°C
Storage Temperature Range..................…………….................................. - 65°C ~ 150°C
TEST CIRCUIT
2
AIC1562
R1
1K
VCC
40mA
Current Source
0.8A
Current Source
1
2
3
2V/0V
IDISCHARG/ ICHG
4
SC
BST
SE
NC
TC
VCC
GND
AIC1562
CT
FB
8
7
6
5
VCC
1.275V
1.225V
1nF
3
AIC1562
ELECTRICAL CHARACTERISTICS (VCC= 5V, Ta=25°°C unless otherwise specified.)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
ICHG
15
25
35
A
IDISCHG
120
150
180
µA
Oscillator
Charging Current
5.0V≤VCC≤20V
Discharge Current
5.0≤VCC≤20V
Voltage Swing
PIN 3
Discharge to Charge Current
Ratio
VIS =VCC
VOSC
0.6
IDISCHG / ICHG
6.0
V
Output Switch
Saturation Voltage, Emitter
Follower Connection
ISE=0.8A;
VBST =VSC = VCC
VCE(SAT)
1.6
2.0
V
Saturation Voltage
ISC=0.8A; IBST =40mA,
(Forced ≅20)
VCE (SAT)
0.5
0.8
V
DC Current Gain
ISC =0.8A; VCE=5.0V
Collector Off-State Current
VCE=20V
IC(OFF)
Ta=25°C
VFB
hFE
35
120
10
nA
Comparactor
Threshold Voltage
0°C ≤Ta ≤70°C
Threshold Voltage Line
Regulation
3.0V ≤VCC≤20V
Input Bias Current
Supply current
1.225
1.25
1.21
1.275
V
1.29
V
mV/V
REGLINE
0.1
0.5
VIN=0V
IIB
0.4
2
µA
VIS =VCC, pin 5>VFB
5.0V ≤VCC≤20V
CT=1nF
PIN 2=GND
Remaining pins open
ICC
1.6
3
mA
4
AIC1562
TYPICAL
PERFORMANCE CHARACTERISTICS
Standby Supply Current vs. Supply Voltage
ICC Supply Current (mA)
1000
2
VCC=5V
VIPK=VCC
PIN 5=GND
100
ON TIME
10
OFF TIME
1
tON-OFF Output Switch ON-OFF Time (µS)
Output Switch ON-OFF Time vs. Oscillator Timing
Capacitor
1
0.1
10
1.8
0.8
0.4
0
100
CT=1nF
VIS=VCC
PIN 2=GND
1.2
0
5
CT, Oscillator Timing Capacitor (nF)
15
20
Emitter Follower Configuration Output Switch
Saturation Voltage vs. Emitter Current
VFB, Threshold Voltage vs Temperature
1.3
1.8
VCE(SAT), Saturation Voltage (V)
VFB,, Threshold Voltage (V)
VCC=5V
CT=1nF
PIN 2=GND
1.28
1.26
1.24
1.22
1.2
10
VCC, Supply Voltage (V)
10
0
20
30
40
50
60
70
80
Temperature (°C)
VCC=5V
PIN 1, 7, 8= VCC
PIN 3, 5= GND
1.6
1.4
1.2
0
0.2
0.4
0.6
0.8
1
IE, Emitter Current Current (A)
Common Emitter Configuration Output Switch
Saturation Voltage vs. Collector Current
VCE(SAT), Saturation Voltage (V)
0.6
VCC=5V
PIN 7=VCC
PIN 2, 3, 5=GND
0.4
0.2
Forced Beta = 20
0
0
0.2
0.4
0.6
0.8
1
Temperature (°C)
5
AIC1562
BLOCK DIAGRAM
1
SC
8
Q2
BST
QS
Q1
R
80
2
SE
7
NC
Is
CT
Oscillator
TC
6
3
Comparator
1.25V
Reference
Voltage
GND
4
VCC
+
-
5
FB
PIN DESCRIPTIONS
PIN 1: SC
- 0.8A switch collector.
PIN 2: SE
- Darlington switch emitter.
PIN 3: TC
- Oscillator timing capacitor.
PIN 4: GND - Power ground.
PIN 5: FB
- Feedback comparator inverting input.
PIN 6: VCC - Power supply input.
PIN 7: NC
-
PIN 8: BST - Bootstrapped driver collector.
6
AIC1562
PHYSICAL DIMENSIONS
8 LEAD PLASTIC SO (unit: mm)
D
SYMBOL
MIN
MAX
A
1.35
1.75
A1
0.10
0.25
B
0.33
0.51
C
0.19
0.25
D
4.80
5.00
E
3.80
4.00
H
E
e
e
A
A1
C
B
1.27(TYP)
H
5.80
6.20
L
0.40
1.27
L
8 LEAD PLASTIC DIP (unit: mm)
D
E1
E
A2
A1
C
L
eB
b
e
SYMBOL
MIN
MAX
A1
0.381
—
A2
2.92
4.96
b
0.35
0.56
C
0.20
0.36
D
9.01
10.16
E
7.62
8.26
E1
6.09
7.12
e
2.54 (TYP)
eB
—
10.92
L
2.92
3.81
7
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