APW7078
Single PWM Switching Controller
Features
•
•
•
•
•
•
•
•
•
2.3 to 5.5V Input Voltage Range
Adjustable Frequency: Maximum 1MHZ
Incorporates Soft-start Function
Built-in Short-circuit Detection Circuit (SCP)
Low Operating Current: Maximum to 1mA
Low Shutdown Current: Maximum to 1mA
Package: MSOP-8, TSSOP-8
Under Voltage Lockout
Lead Free Available (RoHS Compliant)
General Description
The A PW 7078 is a single P W M, s tep-up DC-DC
c ont roller wit h low operating volt age applic at ion
int egr at ing s oft-st art and short circ uit detect ion
function. And the oscillator switching frequency on chip
can be operated by terminating OSC pin to connect
c apac itor and resis t or for adjus t able operating
frequency. Soft-start is adjusted with external capacitor,
whic h s et s t he input current ramp. Bes ides, the
external compensation FB pin will apply the flexibility in
the dynamic loop status, which allow using small, low
equivalent series res istance (ES R) c eramic output
capacitors.
Applications
•
•
•
•
LCD Display Power Source
Camcorders VCRs, MP3 and Digital Still
Camera
Hand-held and Communication Instruments
PDAs
Pinouts
INV
SCP
VDD
CTL
1
2
3
4
8
7
6
5
FB
OSC
GND
OUT
Ordering and Marking Information
APW7078
Lead Free Code
Handling Code
Temp. Range
Package Code
APW7078 X :
APW7078 O :
APW7078
XXX
XX
APW7078
XXXXX
APW7078
Package Code
X : MSOP - 8
O : TSSOP-8
Temp. Range
I : -40 to 85
°
C
Handling Code
TU : Tube
TR : Tape & Reel
Lead Free Code
L : Lead Free Device Blank : Original Device
XXXXX - Date Code
XXXXX - Date Code
No tes : ANPEC lea d-free produ cts co nta in mol din g comp oun ds/die attach m ate ria ls and 10 0% matte in pla te
te rmin atio n fi nish ; wh ich are full y compl iant with Ro HS and compa tibl e wi th both SnPb an d le ad-free sold ieri ng
op era tio ns. AN PEC le ad-free produ cts me et or exceed th e l ead -free req uireme nts of IPC /JEDEC J STD -02 0C
fo r MSL classi ficati on at lea d-fre e p eak re flo w temp era ture.
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
C opyright
©
ANPEC Electronics C orp.
Rev. A.3 - Nov., 2005
1
www.anpec.com.tw
APW7078
Block Diagram
VDD
OSC
UVLO
0.9 V
0.16V
0.1 V
Sawtooth wave
oscillator
VDD
VDD
INV
-
+
Error Amp.
-
+
+
+
DTC 0.8V
PWM
Comp.
Output drive
circuit
OUT
Vref 0.5V
FB
Soft start
SCP
GND
SCP
CTL
Absolute Maximum Ratings
Symbol
V
DD
V
IO
T
A
T
J
T
STG
T
S
Supply Voltage
Input / Output Pins
Operating Ambient Temperature Range
Junction Temperature Range
Storage Temperature Range
Soldering Temperature
Parameter
Value
-0.3 to 7
-0.3 to 7
-40 to 85
-40 to 150
-65 to +150
300, 10 seconds
Unit
V
V
°C
°C
°C
°C
Recommended Operating Condition
Symbol
V
DD
V
INV
V
CTL
C
SCP
R
T
C
T
F
SW
Supply Voltage
Error Amplifier Invert Input Voltage
Control Pin Input Voltage
SCP Pin Capacitor
Timing Resistance
Timing Capacitor
Oscillator Frequency
2
Parameter
Value
Min.
2.3
-0.2
-0.2
-
1.0
100
200
Typ.
-
-
-
0.1
3.3
-
600
Max.
5.5
1
V
DD
-
10
270
1000
Unit
V
V
V
µF
KΩ
pF
KHz
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©
ANPEC Electronics C orp.
Rev. A.3 - Nov., 2005
www.anpec.com.tw
APW7078
Electrical Characteristics
Symbol
Entire Device
V
DD
I
DD
I
SD
Dmax
Supply Voltage
Supply Current
Shutdown Current
Maximum Duty Cycle
V
DD
Startup Threshold
Voltage
Hysteresis voltage
Voltage at Soft-Start
completion
Soft-Start Charge Current
Vscp=0V
V
DD
=2.3V to 5.5V
CTL pin open or VDD
Rt=3.3K, Ct=270pF
80
2.3
0.7
0.1
85
5.5
1
1
92
V
mA
µA
%
Parameter
(T
A
= 25°C, V
DD
= 3.3V, unless otherwise specified)
Test Conditions
APW7078
Min
Typ
Max
Unit
Under Voltage Lockout Protection
V
TH
V
R
-
1.9
-
2.0
1.8
2.1
1.9
V
V
Soft-Start
Vss
Ics
-
0.7
-0.7
0.8
-1.0
0.9
-1.5
V
µA
Short Circuit Protection(SCP)
Vscp
Iscp
Fosc
Fdv
Fdt
Threshold Voltage
Charge Current
Oscillator Frequency
Frequency Stability for
Voltage
Vscp=0V
0.7
-0.7
500
-
-
0.8
-1.0
600
2
5
0.9
-1.5
700
5
-
V
µA
KHz
%
%
Sawtooth waveform oscillator(OSC)
Rt=3.3KΩ, Ct=270pF
V
DD
=2.3V to 5.5V
Ta=-40°C to 85°C
Frequency Stability for
Temperature
Error Amplifier
Vref
Reference Voltage
VFB=INV
V
DD
=2.3V to 5.5V
Ta=-40°C to 85°C
0.49
0.5
5
1
0.51
20
V
mV
%
Vref/dV Vref stability
Vref variation with
Vref/dT
Temperature
gm
Transconductance
I
B
V
OH
V
OL
Input Bias Current
Output Voltage Range
Output Source Current
Output Sink Current
1000
INV=0V
-
-
INV=0V,FB=0.5V
INV=1V,FB=0.5V
-150
140
1.6
1300
1600
1
µA/V
µA
V
V
µA
µA
1.8
0.01
-180
170
-210
200
C opyright
©
ANPEC Electronics C orp.
Rev. A.3 - Nov., 2005
3
www.anpec.com.tw
APW7078
Electrical Characteristics (Cont.)
(T
A
= 25°C, V
DD
= 3.3V, unless otherwise specified)
Symbol
Parameter
Test Conditions
APW7078
Min
-150
150
Typ
-200
200
0.2V
DD
0.8V
DD
Max
Unit
PWM Controller Driver
I
SOURCE
Output Source Current
I
SINK
V
IL
V
IH
Output Sink Current
Control Block
Control Voltage
Active mode
Switch-off mode
Duty<5%, OUT=0V
Duty>5%, OUT=5V
mA
mA
Function Pin Description
Pin No.
1
2
3
4
5
6
7
8
Symbol
INV
SCP
VDD
CTL
OUT
GND
OSC
FB
I/O
I
-
-
I
O
-
-
O
Description
Internal 0.5V reference voltage. Use a resistor divider to set the
output voltage.
Soft-start and short-circuit detection, connects a capacitor from the
pin to ground.
Power supply input pin for IC voltage.
Output control pin. Low = operating mode; High = shutdown mode.
External MOSFET driving pin.
Ground pins of the IC.
Setting capacitor and resister to provide oscillation switching
frequency adjustment.
Error amplifier output pin. Setting circuit for IC compensation.
Application Schematic
VIN
2.5V~4.2V
L1
10uH
C1
22uF
1
INV
2
SCP
3
VDD
C2
0.1uF
C7
1uF
R1
390K
4
CTL
R3
R2
91K
Q2
2N7002
820K
Cp
FB
8
OSC
7
GND
6
OUT
5
C3
270pF
R4
3.3K
C4
0.1uF
D1
VOUT
5V
300mA
SS12
R5
1K
Q1
APM2300A
C5
47uF
C6
0.1uF
*R2≦100KΩ is recommended
33pF
Fig1: APW7078 Step-up Application for Adjust Voltage
C opyright
©
ANPEC Electronics C orp.
Rev. A.3 - Nov., 2005
4
www.anpec.com.tw
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