1.5A Synchronous Buck Converter
with Integrated Power Devices
POWER MANAGEMENT
Description
The SC196A is a synchronous step-down converter with
integrated power devices. The SC196A is designed for
single-cell Li-Ion battery applications but can also be used
in
fi
xed 3.3V or 5V applications. The switching frequency
is nominally set to 1MHz, allowing the use of small
inductors and capacitors. The maximum current rating of
the internal MOSFET switches allows a DC output current
of 1.5A.
Four programable output voltages 1.00V/1.05V/1.20V/
1.80V are available. See SC196 with external feedback
for other output voltage settings.
The SC196A has a
fl
exible clocking methodology that
allows it to be synchronized to an external oscillator or
controlled by the internal oscillator. The device can
operate in either forced PWM mode or in PSAVE mode. If
PSAVE mode is enabled, the part will automatically enter
PFM at light loads to maintain maximum efficiency across
the full load range.
For noise sensitive applications, PSAVE mode can be
disabled by synchronizing to an external oscillator or
pulling the SYNC/PWM pin high. Shutdown turns off all
the control circuitry to achieve a typical shutdown current
of 0.1μA.
SC196A
Features
Up to 93% efficiency
1.00V/1.05V/1.20V/1.80V selectable output voltage
Output current — 1.5A
Quiescent current — 17μA
Input range — 2.7V to 5.5V
Dynamic voltage positioning capability
Fixed 1MHz frequency or 750kHz to 1.25MHz
synchronized operation
PSAVE operation to maximize efficiency at light loads
Minimal external components
Fast transient response
100% duty cycle in dropout
Soft-start
Over-temperature and short-circuit protection
Space-saving lead-free package — MLP-10, 3 x 3mm
Applications
Cell phones
Wireless communication chipset power
Personal media player
Notebook and sub-notebook computers
PDAs and mobile communicators
WLAN peripherals
Typical Application Circuit
SC196A
V
IN
2.7V to 5.5V
C
IN
10μF
VIN
EN
SYNC/PWM
VID0
VID1
MODE
LX
VOUT
PGND
GND
L1
4.7μH
C
OUT
10μF
V
OUT
1.05V
1.5A
July 14, 2008
1
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SC196A
POWER MANAGEMENT
Absolute Maximum Ratings
Parameter
Input Supply Voltage
Logic Inputs
(SYNC/PWM, EN, MODE, VID0, VID1)
Output Voltage
LX Voltage
Thermal Impedance Junction to Ambient
(1)
VOUT Short-Circuit to GND
Operating Ambient Temperature Range
Storage Temperature
Junction Temperature
Peak IR Reflow Temperature
ESD Protection Level
(2)
Symbol
V
IN
V
N
V
OUT
V
LX
θ
JA
t
SC
T
A
T
S
T
J
T
PKG
V
ESD
Maximum
-0.3 to 7
-0.3 to V
IN
+0.3, 7V Max
-0.3 to V
IN
+0.3, 7V Max
-1 to V
IN
+1, -2V(100ns Max),7V Max
40
Continuous
-40 to +85
-60 to +150
-40 to +150
260
2
PRELIMINARY
Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the
Electrical Characteristics section is not recommended.
Units
V
V
V
V
°C/W
s
°C
°C
°C
°C
kV
Note:
(1) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
(2) Tested according to JEDEC standard JESD22-A114-B.
Electrical Characteristics
Unless otherwise noted: V
IN
= 3.6V, EN = V
IN
, SYNC/PWM = V
IN
, MODE = V
IN
, T
A
= -40 to 85°C. Typical values are at T
A
= 25°C.
Parameter
Input Voltage Range
VOUT Accuracy
VOUT Temperature Accuracy
Line Regulation
Load Regulation (PWM)
PSAVE Regulation
P-Channel On Resistance
N-Channel On Resistance
Start-Up Time
P-Channel Current Limit
©
2008 Semtech Corp.
Symbol
V
IN
V
OUT
V
OUT(T)
V
OUT LINE
V
OUT LOAD
V
OUT PSAVE
R
DSP
R
DSN
T
START
I
LIM(P)
Conditions
Min
2.7
Typ
Max
5.5
±1
Units
V
%
%
%
%
%
Ω
Ω
I
OUT
= 0.75A, T
A
= 25°C
I
OUT
= 0.75A, T
A
= -40 to 85°C
V
IN
= 2.7V to 5.5V, V
OUT
= 1.8V,
I
OUT
= 0.75A, T
A
= -40 to 85°C
I
OUT
= 0A to 1.5A, T
A
= -40 to 85°C
SYNC/PWM =GND, C
OUT
=22
μF
I
LX
= 100mA
I
LX
= 100mA
±0.3
±0.4
±0.3
+1.3
-0.3
0.275
0.165
±0.7
±0.65
±0.65
+1.6
-0.6
5
1.9
2
2.63
ms
A
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SC196A
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Parameter
Quiescent Current
Shutdown Current
LX Leakage Current PMOS
LX Leakage Current NMOS
Oscillator Frequency
SYNC Frequency (upper)
SYNC Frequency (lower)
UVLO Threshold (upper)
UVLO Hysteresis
Thermal Shutdown
Thermal Shutdown Hysteresis
Logic Input High
Logic Input Low
Logic Input Current High
Logic Input Current Low
Symbol
I
Q
I
SD
I
LXP
I
LXN
f
OSC
f
SYNCU
f
SYNCL
V
UVL
V
UVLHYS
T
SD
T
SD-HYS
V
IH
V
IL
I
IH
I
IL
EN, SYNC/PWM, VID0, VID1, MODE
EN, SYNC/PWM, VID0, VID1, MODE
EN, SYNC/PWM, VID0, VID1, MODE
EN, SYNC/PWM, VID0, VID1, MODE
-2
-2
0.1
0.1
1.2
0.4
2
2
2.38
2.52
135
145
10
Conditions
SYNC/PWM = GND, I
OUT
= 0A,
V
OUT
= 1.04 x V
OUT(Programmed)
EN = GND, LX = OPEN
LX = GND, EN = GND
LX = 3.6V, EN = GND
-2
0.85
1.25
750
2.65
Min
Typ
17
0.1
0.1
0.1
1.0
1.15
PRELIMINARY
Max
28
1
2
Units
μA
μA
μA
μA
MHz
MHz
kHz
V
mV
°C
°C
V
V
μA
μA
©
2008 Semtech Corp.
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