SC196 [SEMTECH]
1.5A Synchronous Buck Converter with Integrated Power Devices; 1.5A同步降压转换器，集成功率器件
| 型号： | SC196 |
| 厂家： | 
SEMTECH CORPORATION |
| 描述： | 1.5A Synchronous Buck Converter with Integrated Power Devices |
| 文件： | 总18页 (文件大小：657K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SC196
1.5A Synchronous Buck Converter
with Integrated Power Devices
POWER MANAGEMENT
Description
Features
The SC196 is a synchronous step-down converter with Up to 95% efficiency
integrated power devices designed for use in applications VOUT adjustable from less than 0.8V to VIN
using a single-cell Li-ion battery. Its wide input voltage Output current — 1.5A
range also makes it suitable for use in systems with fixed Input range — 2.5V to 5.5V
3.3Vor5Vsupplyrailsavailable.Theswitchingfrequencyis Quiescent current — 17μA
nominally set to 1MHz, allowing the use of small inductors Fixed 1MHz frequency or 750kHz to 1.25MHz
and capacitors. The current rating of the internal MOSFET
switches allows a DC output current of 1.5A.
synchronized operation
PSAVE operation to maximize efficiency at light loads
Shutdown current <1μA
The output voltage is set by connecting a resistor divider Fast transient response
from the filter inductor to the feedback pin. See the 100% duty cycle in dropout
SC196A for pin-programmable output voltages.
Soft-start
Over-temperature and short-circuit protection
The SC196 has a flexible clocking methodology that Lead-free package — MLPD10-UT, 3 x 3 x 0.6 mm
allows it to be synchronized to an external oscillator or
controlled by the internal oscillator. The device operates
in either forced PWM mode or in PSAVE mode. If PSAVE
Applications
mode is enabled, the part will automatically enter PFM at
Cell phones
light loads to maintain maximum efficiency across the full
Wireless communication chipset power
load range.
Personal media players
Microprocessor/DSP core/IO power
For noise sensitive applications, PSAVE mode can be
PDAs and handheld computers
disabled by synchronizing to an external oscillator or
WLAN peripherals
pulling the SYNC/PWM pin high. Shutdown turns off all
USB powered modems
the control circuitry to achieve a typical shutdown current
1 Li-Ion or 3 NiMH/NiCd powered devices
of 0.1μA.
Typical Application Circuit
VOUT
<0.8V to VIN
L1
4.7μH
VIN
2.5V to 5.5V
1.5A
SC196
VIN
LX
CFB1
10pF
VOUT
CIN
10μF
PVIN
RFB1
RFB2
MODE
EN
ADJ
COUT
22μF
SYNC/PWM
PGND
GND
February 8, 2007
www.semtech.com
1
SC196
POWER MANAGEMENT
Absolute Maximum Rating
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.
Parameter
Symbol
Maximum
Units
Input Supply Voltage
VIN
-0.3 to 7
V
Logic Inputs
(N=SYNC/PWM, EN, MODE)
VN
-0.3 to VIN+0.3, 7V Max
V
Output Voltage
VOUT
VADJ
VLX
θJA
-0.3 to VIN+0.3, 7V Max
-0.3 to VIN+0.3, 7V Max
-1 to VIN +1, 7V Max
40
V
V
ADJ Input
LX Voltage
V
Thermal Impedance Junction to Ambient(1)
VOUT Short-Circuit to GND
Operating Ambient Temperature Range
Storage Temperature
°C/W
s
tSC
Continuous
-40 to +85
TA
°C
°C
°C
°C
kV
TS
-65 to +150
-40 to +150
260
Junction Temperature
TJ
Peak IR Reflow Temperature
TPKG
VESD
ESD Protection Level (2)
2
Notes:
(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: VIN = 3.6V, VOUT = 1.8V, EN = VIN, SYNC/PWM = VIN, MODE = VIN , TA = -40 to 85°C. Typical values are at TA = 25°C.
Parameter
Symbol
VIN
Conditions
Min
2.5
Typ
Max
5.5
Units
Input Voltage Range
UVLO Threshold (upper)
UVLO Hysteresis
V
V
VUVL
2.18
2.3
2.45
VUVLHYS
VOUT
150
mV
V
Output Voltage Range
FB Voltage Tolerance
Load Regulation (PWM)
0.8
VIN
0.515
±1
VFB
VIN = 2.5V to 5.5V, IOUT = 0mA to 1.5A 0.485
IOUT = 0mA to 1.5A
0.5
V
VOUT LOAD
±0.5
%
SYNC/PWM=GND,COUT = 22μF,
VIN = 2.5V to 5.5V, IOUT = 0mA to 1.5A
PSAVE Regulation
P-Channel Current Limit
Quiescent Current
VOUT PSAVE
ILIM(P)
IQ
±2
2.8
17
±3
3.57
28
%
A
VIN=2.5V to 5.5V
1.96
SYNC/PWM = GND, IOUT = 0A,
VOUT = 1.04 x VOUT(Programmed)
μA
μA
Shutdown Current
ISD
EN = GND, LX = OPEN
0.1
1
© 2007 Semtech Corp.
www.semtech.com
2
SC196
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Parameter
Symbol
RDSP
RDSN
ILXP
Conditions
ILX = 100mA
Min
Typ
0.275
0.165
0.1
Max
Units
Ω
P-Channel On Resistance
N-Channel On Resistance
LX Leakage Current PMOS
LX Leakage Current NMOS
Oscillator Frequency
SYNC Frequency (upper)
SYNC Frequency (lower)
Start-Up Time
ILX = 100mA
Ω
LX = GND, EN = GND
LX = 3.6V, EN = GND
2
μA
μA
MHz
MHz
kHz
ms
°C
ILXN
-2
0.1
fOSC
0.85
1.25
1.0
1.15
fSYNCU
fSYNCL
tSTART
TSD
750
5
Thermal Shutdown
145
10
Thermal Shutdown Hysteresis
Logic Input High(1)
TSD-HYS
VIH
°C
1.2
V
Logic Input Low(1)
VIL
0.4
2
V
Logic Input Current High(1)
Logic Input Current Low(1)
IIH
-2
-2
0.1
0.1
μA
μA
IIL
2
Note:
(1) For EN, SYNC/PWM, MODE
© 2007 Semtech Corp.
www.semtech.com
3
SC196
POWER MANAGEMENT
Pin Configuration
Ordering Information
DEVICE
PACKAGE
SC196ULTRT(1)(2)
MLPD-UT10 3x3x0.6
Evaluation Board
SC196EVB
Ordering Information
Notes:
PVIN
VIN
1
2
3
4
5
10
9
LX
1) Lead-free packaging only. This product is fully WEEE and RoHS compliant.
2) Available in tape and reel only. A reel contains 3000 devices.
TOP VIEW
PGND
8
SYNC/PWM
EN
GND
MODE
ADJ
7
T
6
VOUT
MLPD-UT: 3X3X0.6, 10 LEAD
Marking Information
196
yyww
xxxx
yy = two digit year of manufacture
ww = two digit week of manufacture
xxxx = lot number
© 2007 Semtech Corp.
www.semtech.com
4
SC196
POWER MANAGEMENT
Pin Descriptions
Pin #
Pin Name Pin Function
Input supply voltage connection to switching FETs — connect the input capacitor between this
pin and PGND directly.
1
PVIN
VIN
2
3
Input supply voltage for control circuits
Oscillator synchronization input. Tie to VIN for forced PWM mode or GND to allow the part to
enter PSAVE mode at light loads. Apply an external clock signal for frequency synchronization.
SYNC/PWM
EN
Enable digital input; a high input enables the SC196, a low disables and reduces quiescent cur-
rent to less than 1ꢀA. In shutdown, LX becomes high impedance.
4
5
Regulated output voltage sense pin — connect to the output capacitor allowing sensing of the
output voltage.
VOUT
Output Voltage Adjust and feedback compensation pin - connect resistor divider between this
pin and GND to set the desired output voltage level.
6
7
ADJ
MODE
MODE select pin — MODE = VIN to select 100% duty cycle function, MODE = GND to disable
this function.
8
9
GND
PGND
LX
Ground
Power Ground
10
Inductor connection to the switching FETs
THERMAL Pad for heatsinking purposes — not connected internally. Connects to ground plane using
PAD multiple vias.
T
© 2007 Semtech Corp.
www.semtech.com
5
SC196
POWER MANAGEMENT
Block Diagram
Plimit Amp
1
PVIN
Current Amp
EN
4
3
SYNC
/PWM
OSC & Slope
Generator
Control
Logic
10
LX
PWM
Comp
PSAVE
Comp
Error Amp
500mV
Ref
Nlimit Amp
9
PGND
7
2
MODE
VIN
8
5
GND
VOUT
ADJ
6
© 2007 Semtech Corp.
www.semtech.com
6
SC196
POWER MANAGEMENT
Applications Information
SC196 Detailed Description
Table 1 — Recommended ADJ Resistor Combinations
The SC196 is a synchronous step-down Pulse Width
Modulated (PWM), DC-DC converter utilizing a 1MHz
fixed-frequency current mode architecture. The device
is designed to operate in a fixed-frequency PWM mode
across the full load range and can enter Power Save Mode
(PSAVE), utilizing Pulse Frequency Modulation (PFM) at
light loads to maximize efficiency.
VOUT(V)
1
RFB2(kΩ)
200
200
200
200
178
200
178
178
178
200
178
178
100
100
100
RFB1(kΩ)
200
240
280
320
357
442
432
464
487
806
820
887
560
620
665
1.1
1.2
1.3
1.5
1.6
1.7
1.8
1.875
2.5
2.8
3
Operation
During normal operation, the PMOS MOSFET is activated
on each rising edge of the internal oscillator. Current
feedback for the switching regulator uses the PMOS
current path, and it is amplified and summed with
the internal slope compensation network. The voltage
feedback loop uses an external feedback divider. The on-
time is determined by comparing the summed current
feedback and the output of the error amplifier. The period
is set by the onboard oscillator or by an external clock
attached to the SYNC/PWM pin.
3.3
3.6
3.8
The SC196 has an internal synchronous NMOS rectifier
and does not require a Schottky diode on the LX pin.
Output Voltage Selection
Continuous Conduction & Oscillator Synchronization
The SC196 is designed to operate in continuous
conduction, fixed-frequency mode. When the SYNC/PWM
pin is tied high the part runs in PWM mode using the
internal oscillator. The part can be synchronized to an
external clock by driving a clock signal into the SYNC/
PWM pin. The part synchronizes to the rising edge of the
clock.
The output voltage can be programmed using a resistor
network connected from VOUT to ADJ to GND. The
combined resistance of the divider chain should be
greater than 10KΩ and less than 1MΩ. Table 1 lists
appropriate resistors which limit the bias current required
of the external feedback resistor chain and ensuring good
noise immunity.
The output voltage can be adjusted between less than
0.8V and VIN. The output voltage formula is:
Protection Features
The SC196 provides the following protection features:
§
·
RFB1
RFB2
¨
¨
¸
ꢀ1
VOUT 0.5u
¸
• Thermal Shutdown
• Current Limit
• Over-Voltage Protection
• Soft-Start
©
¹
VOUT = output voltage (V)
RFB1 = feedback resistor from VOUT to ADJ (Ω)
FB2 = feedback resistor from ADJ to GND (Ω)
R
Thermal Shutdown
Resistors with 1% or better tolerance are recommended
to ensure voltage accuracy.
The device has a thermal shutdown feature to protect the
SC196 if the junction temperature exceeds 145°C. In
thermalshutdown, theon-chippowerdevicesaredisabled,
effectively tri-stating the LX output. Switching will resume
when the temperature drops by 10°C. During this time,
© 2007 Semtech Corp.
www.semtech.com
7
SC196
POWER MANAGEMENT
Applications Information (Cont.)
the output capacitor. The burst-to-off period in PSAVE will
decrease as the load current reduces.
if the output voltage decreases by more than 60% of its
programmed value, a soft-start will be invoked.
The PSAVE switching burst frequency is controlled so that
the inductor current ripple is similar to that in PWM mode.
The minimum switching frequency during this period is
limited to 650kHz.
Current Limit
The PMOS and NMOS power devices of the buck switcher
stage are protected by current limit functions. In the
case of a short to ground on the output, the part enters
frequency foldback mode, which causes the switching
frequency to divide by a factor determined by the output
voltage. This prevents the inductor current from "stair-
casing".
The SC196 automatically detects when to exit PSAVE
mode by monitoring VOUT . For the SC196 to exit PSAVE
mode, the load must be increased, causing VOUT to
decrease until the power save exit threshold is reached.
PSAVE levels are set high to minimize the undershoot
when exiting PSAVE. The lower PSAVE comparator level
is set +0.7% above VOUT, and the upper comparator level
at +1.5% above VOUT, with the exit threshold at -2% below
VOUT.
Over-Voltage Protection
Over-voltage protection is provided on the SC196. In the
event of an over-voltage on the output, the PWM drive is
disabled, effectively tri-stating the LX output. The part will
not resume switching until the output voltage has fallen
2% below the regulation voltage.
If PSAVE operation is required, then a 22μF output
capacitor must be used.
Soft-Start
The soft-start mode is enabled after every shutdown
cycle to limit in-rush current. In conjunction with the
frequency foldback, this controls the maximum current
during start-up. The PMOS current limit is stepped up
through seven soft-start levels to the full value by a timer
driven from the internal oscillator. During soft-start, the
switching frequency is stepped through 1/8, 1/4, 1/2
and full internal oscillator frequency. The time at which
these steps are made is controlled by the output voltage
reaching predefined threshold levels. When the output
voltage is within 2% of the regulation voltage, soft-start
mode is disabled.
Higher Load
Applied
BURST
OFF
1.5%
0.7%
PSAVE Mode at Light Load
PWM Mode at Medium/
High Load
VOUT
-2%
Inductor Current
Power Save Mode Operation
0 A
The PSAVE mode may be selected by tying the SYNC/PWM
pin to GND. Selecting PSAVE mode will enable the SC196
to automatically activate/deactivate operation at light
loads, maximizing efficiency across the full load range.
The SC196 automatically detects the load current at which
it should enter PSAVE mode. The SC196 is optimized to
track maximum efficiency with respect to VIN.
Time
Figure 1 — Power Save Operation
100% Duty Cycle Operation
The 100% duty cycle mode may be selected by connecting
the MODE pin high. This will allow the SC196 to maintain
output regulation under conditions of low input voltage/
high output voltage conditions.
In PSAVE mode, VOUT is driven from a lower level to an
upper level by a switching burst. Once the upper level has
been reached, the switching is stopped and the quiescent
current is reduced. VOUT falls from the upper to lower levels
in this low current state as the load current discharges
In 100% duty cycle operation, as the input supply drops
toward the output voltage, the PMOS on-time increases
linearly above the maximum value in fixed-frequency
operation until the PMOS is active continuously. Once
© 2007 Semtech Corp.
www.semtech.com
8
SC196
POWER MANAGEMENT
Applications Information (Cont.)
the PMOS is switched on continuously, the output voltage
tracks the input voltage minus the voltage drop across
the PMOS power device and inductor according to the
following relationship:
Table 1 — Recommended Inductors
Rated
Current
(A)
Dimensions
LxWxH
Value
(μH)
DCR
(Ω)
Tolerance
(%)
Manufacturer/Part #
(mm)
VOUT = VIN - IOUT x (RDSP + RIND)
BI Technologies
HM66404R1
4.1
4.7
4.7
4.7
4.7
4.7
4.7
0.057
0.09
1.95
1.5
20
20
30
30
20
30
20
5.7 × 5.7 ×2.0
6.6 × 4.5 × 3.0
4.0 × 4.0 × 2.0
5.0 × 5.0 × 2.0
5.0 × 5.0 × 2.0
3.8 × 3.8 × 1.8
3.0 × 3.0 × 1.5
Coilcraft
D01608C-472ML
where
VOUT = Output voltage
VIN = Input voltage
IOUT = Output current
RDSP = PMOS switch ON resistance
RIND = Series resistance of the inductor
TDK
0.098
0.050
0.087
0.050
0.2
1.24
1.2
VLCF4020T- 4R7N1R2
Taiyo Yuden
LMNP04SB4R7N
TOKO
D52LC
1.14
1.2
Sumida
CDRH3D16
Inductor Selection
TheSC196isdesignedforusewitha4.7ꢀHinductor.Where
VOUT > 3.8V is required, a 10ꢀH inductor is recommended.
The magnitude of the inductor current ripple depends on
the inductor value and can be determined by the following
equation:
Coilcraft
LPS3015
1.1
Note: recommended Inductors do not necessarily guarantee rated perfor-
mance of the part.
§
·
VOUT
VOUT
COUT Selection
¨
¨
¸
¸
'IL
1ꢁ
The internal compensation is designed to work with a
certain output filter corner frequency defined by the
equation:
Lu fosc
V
IN
©
¹
This equation demonstrates the relationship between
input voltage, output voltage, and inductor ripple current.
1
fC
2S Lu COUT
The inductor should have a low DCR to minimize the
conduction losses and maximize efficiency. As a minimum
requirement, the DC current rating of the inductor
should be equal to the maximum load current plus half
of the inductor current ripple as shown by the following
equation:
This filter has a single pole and is designed to operate with
a minimum output capacitor value of 10ꢀF. Larger output
capacitor values will improve transient performance.
If PSAVE operation is required, the minimum capacitor
value is 22μF.
'IL
2
IL(PK) IOUT(MAX)
ꢀ
Output voltage ripple is a combination of the voltage
ripple from the inductor current charging and discharging
the output capacitor and the voltage created from the
inductor current ripple through the output capacitor ESR.
Selecting an output capacitor with a low ESR will reduce
the output voltage ripple component, as can be seen in
the following equation:
Final inductor selection will depend on various design con-
siderations such as efficiency, EMI, size and cost. Table 2
lists the manufacturers of practical inductor options.
CIN Selection
The source input current to a buck converter is non-
continuous. To prevent large input voltage ripple, a low
ESR ceramic capacitor is required. A minimum value of
10ꢀF should be used for input voltage filtering, while a
22ꢀF capacitor is recommended for improved input
voltage filtering.
ΔVOUT(ESR) = ΔIL(RIPPLE) x ESRCOUNT
Capacitors with X7R or X5R ceramic dielectric are strongly
recommended for their low ESR and superior temperature
© 2007 Semtech Corp.
www.semtech.com
9
SC196
POWER MANAGEMENT
Applications Information (Cont.)
and voltage characteristics. Y5V capacitors should not
be used as their temperature coefficients make them
unsuitable for this application. Attention should be paid to
the DC voltage characteristics of the ceramic capacitors
to be used for both input and output. Parts with different
case sizes can vary significantly. For example a 22μF
X5R 0805 capacitor with 3.6V DC applied could have a
capacitance as low as 12μF. When a 1206 size part is
used, the capacitance is approximately 20μF. Table 3 lists
the manufacturers of recommended capacitor options.
Table 3 — Recommended Capacitors
Rated
Voltage
(VDC)
Value
(μF)
Temperature
Characteristic
Manufacturer/Part #
Case Size
Murata
GRM21BR60J226ME39L
22
22
10
10
6.3
16
X5R
X5R
X5R
X5R
0805
1210
0603
0603
Murata
GRM422X5R226
K16H533
Murata
GRM188R60J106
MKE19
6.3
6.3
TDK
C2012X5R0J106K
Note: Where PSAVE operation is required, 22μF must be used for COUT
.
Feed-Forward Compensation Capacitor
A small 10pf compensation capacitor, CFB1 is required
to ensure correct operation. This capacitor should
be connected directly across feedback resistor RFB1
.
Capacitors with X7R or X5R ceramic dielectric are
strongly recommended for their superior temperature
characteristics.
© 2007 Semtech Corp.
www.semtech.com
10
SC196
POWER MANAGEMENT
Applications Information (Cont.)
PCB Layout Considerations
Poor layout can degrade the performance of the DC-DC
converter and can contribute to EMI problems, ground
bounce and resistive voltage losses. Poor regulation and
instability can result.
2. Route the output voltage feedback path away from the
inductor and LX node to minimize noise and magnetic
interference. Keep RFB1 and RFB2 close to the ADJ pin
to avoid noise pickup.
3. Maximize ground metal on the component side to
improvethereturnconnectionandthermaldissipation.
Separation between the LX node and GND should be
maintained to avoid coupling of switching noise to the
ground plane.
A few simple design rules can be implemented to ensure
good layout:
4. Use a ground plane with several vias connecting to
the component side ground to further reduce noise
interference on sensitive circuit nodes.
1. Place the inductor and filter capacitors as close to the
device as possible and use short wide traces between
the power components.
GND
LOUT
CIN
VIN
LX
VOUT
COUT
GND
SC196
SYNC/PWM
EN
MODE
CFB1
RFB2
RFB1
GND
© 2007 Semtech Corp.
www.semtech.com
11
SC196
POWER MANAGEMENT
Typical Characteristics
Efficiency vs. Load Current VOUT = 2.5V
Efficiency vs. Load Current VOUT = 3.3V
RFB1+RFB2=10Kꢀ
RFB1+RFB2=10Kꢀ
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
VIN=3.3V PSAVE
VIN=3.9V PSAVE
VIN=3.3V PWM
VIN=4.2V PWM
VIN=3.2V PWM
VIN=4.2V PWM
VIN=5.0V PWM
VIN=4.2V PSAVE
VIN=5.0V PSAVE
VIN=4.2V PSAVE
VIN=5.0V PSAVE
VIN=5.0V PWM
30
20
10
0
0.001
0.0001
0.01
0.1
1
10
0.0001
0.001
0.01
0.1
1
10
IOUT(A)
IOUT(A)
Efficiency vs. Load Current VOUT = 1.0V
Efficiency vs. Load Current VOUT = 1.8V
RFB1+RFB2=10Kꢀ
R
FB1+RFB2=10Kꢀ
100
90
80
70
60
100
90
80
70
60
50
40
30
20
10
0
VIN=2.7V PSAVE
VIN=2.7V PSAVE
VIN=2.7V PWM
VIN=3.6V PWM
VIN=4.2V PWM
VIN=3.6V PSAVE
VIN=4.2V PSAVE
VIN=3.6V PSAVE
VIN=4.2V PSAVE
50
40
VIN=2.7V PWM
VIN=3.6V PWM
VIN=4.2V PWM
30
20
10
0
0.001
0.0001
0.001
0.01
0.1
1
10
0.0001
0.01
0.1
1
10
IOUT(A)
IOUT(A)
PWM to PSAVE Hysteresis
Efficiency vs. Input Voltage
I
OUT=750mA (PWM) / 50mA (PSAVE), RFB1+RFB2=10Kꢀ
VIN=3.6V, VOUT=1.8V
100
95
90
85
80
75
70
65
60
1.82
VOUT=3.3V PWM
1.815
1.81
VOUT=3.3V PSAVE
VOUT=1.0V PWM
PSAVE Exit
OUT Increasing
1.805
PSAVE Entry
IOUT Decreasing
VOUT=1.0V PSAVE
I
1.8
1.795
0
0.1
0.2
0.3
IOUT(A)
0.4
0.5
0.6
2.4
2.8
3.2
3.6
4.0
4.4
4.8
5.2
5.6
VIN(V)
© 2007 Semtech Corp.
www.semtech.com
12
SC196
POWER MANAGEMENT
Typical Characteristics (Cont.)
VOUT vs. VIN
Load Regulation
VIN=3.6V, VOUT=1.8V
VOUT=1.8V, IOUT=750mA(PWM)/50mA(PSAVE)
1.82
1.82
1.815
1.81
PSAVE
1.81
PSAVE
1.8
PWM
1.805
1.8
1.79
1.78
1.77
1.76
PWM
1.795
1.79
1.785
2.4
2.8
3.2
3.6
4
4.4
IN(V)
4.8
5.2
5.6
6
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
V
I
OUT(A)
VOUT vs. Temperature VOUT=1.8V
Current Limit
VIN=3.6V, VOUT=1.8V, PWM
VIN=3.6V, VOUT=1.8V, IOUT=100mA
2
1.8
1.6
1.4
1.2
1
1.798
1.796
1.794
1.792
1.79
PSAVE
1.788
1.786
1.784
0.8
0.6
0.4
0.2
0
PWM
20
1.782
1.78
1.778
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
IOUT(A)
2
2.2 2.4
-60
-40
-20
0
40
60
80
100
TA(°C)
Quiescent Current vs. Input Voltage, PSAVE Mode
Quiescent Current vs. Input Voltage, PWM Mode
PSAVE Mode
22
PWM Mode
6
21
TA=-40°
C
C
TA=85°
C
TA=85°
TA=25°
C
C
5.5
5
20
19
18
17
16
15
14
13
12
TA=25°
4.5
4
TA=-40°
C
3.5
3
2.5
3
3.5
4
4.5
5
5.5
6
2.5
3
3.5
4
4.5
5
5.5
6
VIN(V)
V
IN(V)
© 2007 Semtech Corp.
www.semtech.com
13
SC196
POWER MANAGEMENT
Typical Characteristics (Cont.)
P-Channel RDSON vs. Input Voltage
N-Channel RDSON vs. Input Voltage
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.22
0.20
0.18
TA=85°
C
C
TA=85°
C
C
TA=25°
TA=25°
0.16
0.14
TA=-40°
C
TA=-40°
C
0.12
0.10
2.7
3.2
3.7
4.2
IN(V)
4.7
5.2
2.7
3.2
3.7
4.2
VIN(V)
4.7
5.2
V
Switching Frequency vs. Temperature
100% Duty Cycle Mode
VIN=3.4V, VOUT=3.3V, IOUT=150mA, PWM
1050
1040
1030
1020
1010
1000
990
VIN=5.5V
VIN=3.6V
V
OUT (20mV/div)
ILX (200mA/div)
VIN=2.7V
VLX (2V/div)
980
970
960
950
Time (2ꢁs/div)
-50
-30
-10
10
30
TJ(°C)
50
70
90
110
130
PSAVE Operation
PWM Operation
VIN=3.6V, VOUT=1.8V, IOUT=150mA, PSAVE
VIN=3.6V, VOUT=1.8V, IOUT=150mA, PWM
VOUT (20mV/div)
ILX (500mA/div)
VOUT (50mV/div)
I
LX (500mA/div)
V
LX (5V/div)
VLX (2V/div)
Time (1ꢁs/div)
Time (2ꢁs/div)
© 2007 Semtech Corp.
www.semtech.com
14
SC196
POWER MANAGEMENT
Typical Characteristics (Cont.)
PSAVE Start-up
PWM Start-up
VIN=3.6V, VOUT=1.8V, IOUT=1.5A, PWM
VIN=3.6V, VOUT=1.8V, IOUT=10mA, PSAVE
V
EN (5V/div)
VEN (5V/div)
VOUT (1V/div)
VOUT (1V/div)
IIN (500mA/div)
I
IN (100mA/div)
Time (1ms/div)
Time (100ꢁs/div)
Load Transient Response-1
Load Transient Response-2
VIN=3.6V, VOUT=1.8V, IOUT=100mA to 1.5A, PWM
VIN=3.6V, VOUT=1.8V, IOUT=10mA to 1.5A, PWM
VOUT (200mV/div)
VOUT (200mV/div)
I
OUT (500mA/div)
IOUT (500mA/div)
Time (400ꢁs/div)
Time (400ꢁs/div)
Load Transient Response-3
Load Transient Response-4
VIN=3.6V, VOUT=1.8V, IOUT=100mA to 1.5A, PSAVE
VIN=3.6V, VOUT=1.8V, IOUT=10mA to 1.5A, PSAVE
VOUT (200mV/div)
VOUT (200mV/div)
I
OUT (500mA/div)
IOUT (500mA/div)
Time (400ꢁs/div)
Time (400ꢁs/div)
© 2007 Semtech Corp.
www.semtech.com
15
SC196
POWER MANAGEMENT
Applications Circuits
VOUT Programmed to 1.2V, no PSAVE
VOUT
1.2V
1.5A
L1
4.7μH
VIN
2.5V to 5.5V
SC196
VIN
LX
RFB1
CFB1
10pF
VOUT
280k
CIN
10μF
PVIN
MODE
EN
0.1%
COUT
10μF
ADJ
RFB2
200k
0.1%
SYNC/PWM
PGND
GND
The output voltage is set at 1.2V by the selection of the two resistors RFB1 and RFB2, using resistor values from
Table 1. PWM-only mode operation is selected by connecting the SYNC/PWM pin to the VIN pin. The 100% duty cycle
capability is selected by connecting the MODE pin to the VIN pin. A 10μF capacitor is selected for the output, as PSAVE
operation is not required in this application.
© 2007 Semtech Corp.
www.semtech.com
16
SC196
POWER MANAGEMENT
Outline Drawing — MLPD-UT10 3x3x0.6
DIMENSIONS
INCHES MILLIMETERS
A
E
B
E
DIM
MIN NOM MAX MIN NOM MAX
-
-
-
-
A
.018
A1 .000
A2
.024 0.45
.002 0.00
.60
0.05
(.006)
(0.1524)
b
C
D
E
e
.007 .009 .011 0.18 0.23 0.30
.074 .079 .083 1.87 2.02 2.12
.042 .048 .052 1.06 1.21 1.31
.114 .118 .122 2.90 3.00 3.10
PIN 1
INDICATOR
.020 BSC
0.50 BSC
(LASER MARK)
L
.012 .016 .020 0.30 0.40 0.50
N
10
10
aaa
bbb
.003
.004
0.08
0.10
A
SEATING
PLANE
aaa
C
A1
C
A2
C
1
2
LxN
D
N
e
bxN
bbb
C A B
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS.
© 2007 Semtech Corp.
www.semtech.com
17
SC196
POWER MANAGEMENT
Land Pattern — MLPD-UT10 3x3x0.6
DIMENSIONS
INCHES MILLIMETERS
K
DIM
(.112)
.075
.055
.087
.020
.012
.037
.150
(2.85)
1.90
1.40
2.20
0.50
0.30
0.95
3.80
C
G
H
K
P
X
Y
Z
H
X
G
Y
(C)
Z
P
NOTES:
1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
2. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD
SHALL BE CONNECTED TO A SYSTEM GROUND PLANE.
FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR
FUNCTIONAL PERFORMANCE OF THE DEVICE
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 FAX (805) 498-3804
www.semtech.com
© 2007 Semtech Corp.
www.semtech.com
18
相关型号：
SC1972
NPN EPITAXIAL PLANAR TYPE(for RF power amplifiers on VHF band Mobile radio applications)
MITSUBISHI
©2020 ICPDF网 联系我们和版权申明