SD6273VIR1 [SHOUDING]
1.2MHz Step-Up PWM Controller;
| 型号： | SD6273VIR1 |
| 厂家： | 
SHOUDING Shouding Semiconductor |
| 描述： | 1.2MHz Step-Up PWM Controller |
| 文件： | 总9页 (文件大小：1263K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Shouding
1.2MHz Step-Up PWM Controller
SD6273
FEATURES
DESCRIPTION
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
VDD Range: 2.7V to 5.5V
High Efficiency up to 90%
The SD6273 is a compact, high efficiency, fixed
frequency pulse-width-modulation (PWM) controller.
It provides an easy-to-use power supply solution for
the application from one Li-ion battery to 5V output.
All compensation and protection circuitry are
integrated to minimize external components. The
1.2MHz high switching frequency allows smaller
inductor and output capacitor, making the SD6273
ideally suited for small battery-powered applications
and saves PCB space.
1.2MHz Fixed Switching Frequency
Tiny External Components
Output Short Protection
<1ꢀA Shutdown Current
3.3V to +5.0V Distributed Power Supply
Single Cell Li-ion Battery to 5V Converter
Available in SOT23-5 and SOT23-6 Packages
The SD6273 contains thermal shutdown function and
output short protection circuit. Built-in soft-start
circuitry prevents excessive inrush current during
start-up.
RoHS Compliant and 100% Lead (Pb)-Free
Halogen-Free
APPLICATIONS
The SD6273 is available in a Pb-free, thin-SOT23-5
and SOT23-6 packages.
ꢀ
ꢀ
One Li-Ion Battery to 5V Output
Handheld Devices
Typical Application Circuit
SD6273
Figure 1. Connecting VDD to VIN
SD6273 Ver1.1 Dec. 2012
www.shouding.net
1
Shouding
1.2MHz Step-Up PWM Controller
SD6273
Typical Application Circuit (Continued)
SD6273
Figure 2. Connecting VDD to VOUT
Pin Configurations
Package
Type
Package
Type
Pin Configurations
Pin Configurations
SOT23-5
SOT23-6
Pin Description
PIN
EN
SOT23-5
SOT23-6
DESCRIPTION
Enable input. EN is an active high asserted input. Set EN lower than 0.4V
will disable SD6273.
1
2
3
4
5
6
GND
EXT
Ground.
Output of MOSFET gate driver. Connect this pin to the gate of the external
MOSFET.
Power input. Connect VDD to the input power supply or to the output of the
regulator.
VDD
4
1
FB
5
-
3
2
Feedback pin.
No connect.
NC
SD6273 Ver1.1 Dec. 2012
www.shouding.net
2
Shouding
1.2MHz Step-Up PWM Controller
SD6273
Ordering Information
Order Number
Package Type
Marking
Operating Temperature Range
xxxxx
An00
xxxxx
An00
SD6273VIR1
SOT23-5
-40 °C to 85°C
SD6273VAIR1
SOT23-6
-40 °C to 85°C
SD6273□ □ □ □
□
Lead Free Code
1: Lead Free, Halogen Free
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type
V : SOT23-5
VA: SOT23-6
Block Diagram
Figure 3.
SD6273 Ver1.1 Dec. 2012
www.shouding.net
3
Shouding
1.2MHz Step-Up PWM Controller
SD6273
Absolute Maximum Ratings (1)
ꢁ
ꢁ
ꢁ
ꢁ
FB, EN to GND --------------------------------------------------------------------- -0.3V to 6V
Supply Voltage ,VDD ---------------------------------------------------------------- -0.3V to 6V
Output of Gate Driver, EXT ------------------------------------------------------- -0.3V to 6V
Power Dissipation, PD@ TA=25°C
V
SOT23-5, SOT23-6 ------------------------------------------------------------------ 0.488W
Package Thermal Resistance
ꢁ
SOT23-5, SOT23-6, θJA ------------------------------------------------------------ 205°C/W
Operating Temperature Range ----------------------------------------------------- -40°C to 85°C
Lead Temperature (Soldering, 10sec.) -------------------------------------------- 260°C
Storage Temperature Range ------------------------------------------------------- -65°C to 150°C
ꢁ
ꢁ
ꢁ
ꢁ
ESD Susceptibility (HBM) --------------------------------------------------------
2kV
Recommend Operating Conditions (2)
ꢁ
ꢁ
Junction Temperature Range ------------------------------------------------------- -40°C to 125°C
Supply Voltage , VDD----------------------------------------------------------------- 2.7V to 5.5V
Note (1): Stress beyond those listed under “Absolute Maximum Ratings” may damage the device.
Note (2): The device is not guaranteed to function outside the recommended operating conditions.
Electrical Characteristics
VDD =3.6V, TA= 25°C, unless otherwise noted.
SD6273
Typ. Max.
Symbol
Parameter
Conditions
Unit
Min.
Power Supply
VDD
IQ
Input Voltage Range
Supply Current
2.7
5.5
650
1
V
µA
µA
V
EN=VDD=3.6V
500
IS
VDD Shutdown Current
VDD=3.6V, EN = GND
Rising
VUVLO Under-Voltage Lockout
2.2
2.35
80
2.5
Under-Voltage Lockout
Hysteresis
VUVLO_HYS
mV
FOSC
VFB
IFB
Switching Frequency
Feedback Voltage
TA = 25°C
1.0
1.2
0.6
1.4
0.612
0.2
MHz
V
0.588
FB Input/Output Current
µA
%
DMAX Maximum Duty Cycle
80
85
90
IEXTH High Side Output Current
VEXT=VDD-0.4V
VEXT=0.4V
150
200
200
300
mA
mA
IEXTL
Low Side Output Current
Thermal Shutdown
Threshold
Thermal Shutdown
Hysteresis
TSD
150
30
°C
°C
TSD(HYS)
EN Logic Control
VEN(L) EN, Input Low Threshold
VEN(H) EN, Input High Threshold
0.4
V
V
1.4
IENH
IENL
EN Input Current
EN Input Current
EN = 6V
EN = 0V
0.1
0.1
µA
µA
SD6273 Ver1.1 Dec. 2012
www.shouding.net
4
Shouding
1.2MHz Step-Up PWM Controller
SD6273
Typical Operating Characteristics
Line Regulation
(VIN=3.6V→4.2V,VOUT=5V,L=2.2ꢀH,COUT=44ꢀF,RL=5ꢁ)
IOUT vs. Efficiency
1
VIN
1V/div
0.9
0.8
VIN=3V
VOUT
VIN=3.3V
VIN=3.6V
VIN=3.9V
VIN=4.2V
200mV/div
0.7
0.6
IOUT
1A/div
0
500
1000
1500
2000
IOUT(mA)
80ꢀs/div
Power On
Power On
(VIN=3.6V,VOUT=5V,L=2.2ꢀH,COUT=44ꢀF,RL=5ꢁ)
(VIN=3.6V,VOUT=5V,L=2.2ꢀH,COUT=44ꢀF,RL=∞)
VIN
VIN
2V/div
VOUT
2V/div
2V/div
VOUT
2V/div
IIN
500mA/div
IIN
50mA/div
4ms/div
4ms/div
Load Regulation 300→0mA
Load Regulation 0→300mA
(VIN=3.6V,VOUT=5V,L=2.2ꢀH,COUT=44ꢀF)
(VIN=3.6V,VOUT=5V,L=2.2ꢀH,COUT=44ꢀF)
VOUT
VOUT
1V/div
1V/div
IOUT
100mA/div
IOUT
100mA/div
2ms/div
80ꢀs /div
SD6273 Ver1.1 Dec. 2012
www.shouding.net
5
Shouding
1.2MHz Step-Up PWM Controller
SD6273
UVLO Function
Operation
The SD6273 has a UVLO (under voltage lock out)
circuit for avoiding IC malfunctions due to power supply
voltage drops. The SD6273 stops switching operation
upon UVLO detection and retains the external transistor
in the off state. Once entering the UVLO detection status,
the soft-start function is reset.
The SD6273 is a switching regulator controller with
pulse width modulation（PWM）. In SD6273, pulses are
skipped in light load to save energy.
The SD6273 uses
a
1.2MHz fixed-frequency,
voltage-mode regulation architecture to regulate the
output voltage. It senses the output voltage through an
external resistive voltage divider and compares that to
the internal 0.6V reference to generate the error voltage,
which is used to control the duty cycle and regulates the
VOUT to the set value.
When the SD6273 is disabled (EN = Low), EXT will
be pull down to turn off external NMOS. When enabled
(EN = High), SD6273 will operate in force PWM
mode for regulating the output voltage to the target
value.
Application Information
Setting the Output Voltage
Set the output voltage by selecting the resistive voltage
divider ratio. The voltage divider drops the output
voltage to the 0.6V feedback voltage. Use 110kꢁ
resistor for RFB1 of the voltage divider. Determine the
low-side resistor RFB2 by the equation:
R
+ R
The SD6273 is a step-up switching regulator controller.
Figure 4. shows the basic circuit diagram. Step-up
switching regulator starts the current supplied by the
input voltage (VIN) when the NMOS is turned on and
holds energy in the inductor at the same time. When the
NMOS is turned off, the voltage of node SW is stepped
up to discharge the energy held in the inductor and the
current is discharged to VOUT through the Shottky diode.
Once the discharged current is stored in COUT, the
potential of VOUT increases until the voltage of the FB
pin reaches the same potential as the internal reference
voltage.
V
FB2
OUT
FB1
R
=
V
FB
FB2
Where VOUT is the output voltage; FB is the 0.6V
feedback voltage. And when VOUT is 5.0V, RFB2 is 15kꢁ.
Selecting the Input Capacitor
An input capacitor is required to supply the AC ripple
current to the inductor, while limiting noise at the input
source. Multi-layer ceramic capacitors are the best
choice as they have extremely low ESR and are
available in small footprints. Use an input capacitor
value of 10ꢀF or greater. This capacitor must be placed
physically close to the device.
Selecting the Output Capacitor
A single 22ꢀF ceramic capacitor usually provides
sufficient output capacitance for most applications.
Larger values up to 44ꢀF may be used to obtain
extremely low output voltage ripple and improve
transient response. The impedance of the ceramic
capacitor at the switching frequency is dominated by the
capacitance, therefore the output voltage ripple is mostly
independent of the ESR. The output voltage ripple
VRIPPLE is calculated as:
Figure 4.
For the PWM control method, the switching frequency
(fsw) is fixed and the VOUT voltage is held constant
according to the ratio of the ON time and OFF time (ON
duty) of NMOS in each period.
I
(V
− V )
LOAD OUT IN
V
=
RIPPLE
V
× C
× f
OUT SW
OUT
Where VIN is the input voltage, ILOAD is the load current,
COUT is the output capacitor and fSW is the 1.2MHz
switching frequency.
The ON duty in the current continuous mode can be
calculated by using the equation below. Use the
SD6273 in the range where the ON duty is less than the
maximum duty. Note that the NMOS will be turned off
when the voltage of FB pin is smaller than 0.2V.
Selecting the Inductor
The inductor is required to force the output voltage
higher while being driven by the lower input voltage. A
good rule for determining the inductance is to allow the
peak-to-peak ripple current to be approximately
30%-50% of the maximum input current. Calculate the
required inductance value L using the equations:
Soft-Start
The SD6273 includes a soft-start timer that steps up
output voltage to prevent excessive current at the input.
This will prevent premature termination of the source
voltage at startup due to inrush current, and also force
the input current to rise slowly to regulate the output
voltage during soft-start.
SD6273 Ver1.1 Dec. 2012
www.shouding.net
6
Shouding
1.2MHz Step-Up PWM Controller
SD6273
V (V
− V )
IN OUT
IN
L =
V
× ∆I×f
SW
OUT
V
× I
LOAD(MAX)
OUT
I
=
IN(MAX)
V ×η
IN
Where ILOAD(MAX) is the maximum load current, ∆I is
the peak-to-peak inductor ripple current and η is
efficiency. For the SD6273, typically 2.2 ꢀH is
recommended for most applications. Choose an inductor
that does not saturate at the peak switching current as
calculated above with additional margin to cover heavy
load transients and extreme startup conditions.
Layout Considerations
High frequency switching regulators require very careful
layout for stable operation and low noise. All
components must be placed as close to the IC as possible.
All feedback components must be kept close to the FB
pin to prevent noise injection on the FB pin trace. The
ground return of CIN and COUT should be tied close to the
GND pin. See the SD6273 demo board layout for
reference.
SD6273 Ver1.1 Dec. 2012
www.shouding.net
7
Shouding
1.2MHz Step-Up PWM Controller
SD6273
Packaging Information
SOT23-5
MILLIMETERS
INCHES
Normal
-
SYMBOLS
MIN.
-
Normal
MAX.
1.40
0.15
3.15
1.80
3.00
0.60
0.50
MIN.
-
MAX.
A
A1
D
E1
E
-
-
0.055
0.006
0.124
0.071
0.118
0.024
0.020
0.00
2.65
1.40
2.60
0.30
0.30
0.000
0.104
0.055
0.102
0.012
0.012
-
2.90
1.60
2.80
0.45
-
0.114
0.063
0.110
0.018
-
L
b
e
0.95 REF
0.037REF
SD6273 Ver1.1 Dec. 2012
www.shouding.net
8
Shouding
1.2MHz Step-Up PWM Controller
SD6273
SOT23-6
MILLIMETERS
INCHES
Normal
-
SYMBOLS
MIN.
1.00
Normal
-
MAX.
1.45
MIN.
0.039
MAX.
A
A1
b
0.057
0.006
0.020
0.122
0.069
0.00
0.30
2.70
1.45
-
0.15
0.50
3.10
1.75
0.000
0.012
0.106
0.057
-
-
-
2.90
D
E1
e
0.114
0.063
0.037 BSC
0.110
-
1.60
0.95 BSC
2.80
E
2.60
0.30
3.00
0.60
0.102
0.012
0.118
0.024
L
-
SD6273 Ver1.1 Dec. 2012
www.shouding.net
9
相关型号：
©2020 ICPDF网 联系我们和版权申明