|
uPI Semiconductor |
uP7706
3A Ultra Low Dropout Linear Regulator
General Description
Features
The uP7706 is a 3A ultra low dropout linear regulator
specifically designed for motherboard and notebook
applications. This device works with dual supplies, a control
input for the control circuitry and a power input as low as
1.2V for providing current to output. The uP7706 delivers
high-current and ultra-low-drop output voltage as low as
0.8V for applications where VOUT is very close to VIN.
The uP7706 features comprehensive control and protection
functions: a power on reset (POR) circuit for monitoring
both control and power inputs for proper operation; an EN
input for enabling or disabling the device, a power OK with
time delay for indicating the output voltage status, a
foldback current limit function, and a thermal shutdown
function.
The uP7706 is available in PSOP-8 or VDFN6x5-8L
packages with very low thermal resistance.
Applications
Desktop PCs, Notebooks, and Workstations
Graphic Cards
Low Voltage Logic Supplies
Microprocessor and Chipset Supplies
Split Plane Microprocessor Supplies
Advanced Graphics Cards Supplies
SoundCards and Auxiliary Power Supplies
SMPS Post Regulators
www.DataSheet4U.com
Works with 1.2~5.5V VIN
Adjustable Output Voltage, Down to 0.8V
1.5% Initial Accuracy
Excellent Line and Load Regulation
3A Guaranteed Output Current
200mV @ 2A Dropout Voltage
Very Low On-Resistance
100mΩ typical
VOUT Pull Low Resistance when Disabled
Low Reverse Leakage (Output to Input )
VOUT Power OK Signal
Fast Transient Response
Low External Component Count
Low Cost and Easy to Use
Enable Pin
Over Current and Over Temperature Protection
Ordering Information
Order Number Package Type
Remark
uP7706U8
PSOP-8
uP7706ADC8 VDFN6x5 - 8L
Note: uPI products are compatible with the current IPC/
JEDEC J-STD-020 and RoHS requirements. They are
100% matte tin (Sn) plating and suitable for use in SnPb
or Pb-free soldering processes.
Pin Configuration & Typical Application Circuit
POK
EN
VIN
CNTL
18
27
GND
36
45
PSOP-8
GND
FB
VOUT
NC
POK 1
EN 2
VIN 3
CNTL 4
GND
8 GND
7 FB
6 VOUT
5 NC
DFN6x5-8L
5VCC
C1
0.1uF
VIN
C2
22uF
CNTL
EN
2
4
POK
1
VIN
3
VOUT
6
FB
7
8
GND
R3
10K
R2
12.5K
R1
10K
VOUT
C4
option
C3
100uF
uPI Semiconductor Corp., http://www.upi-semi.com
Rev. F00, File Name: uP7706-DS-F0000
1
uP7706
Functional Pin Description
Pin No.
1
2
3
4
5
6
7
8
Exposed
Pad
Name Pin Function
POK
Power OK Indication. This pin is an open-drain output and is set high impedance once VOUT
reaches 92% of its rating voltage.
EN
Enable Input. Pulling this pin below 0.8V turns the regulator off, reducing the quiescent current
to a fraction of its operating value.
Input Voltage. This is the drain input to the power device that supply current to the output pin.
VIN
Large bulk capacitors with low ESR should be placed physically close to this pin o prevent the
input rail from dropping during large load transient. A 10uF ceramic capacitor is recommended
at this pin.
CNTL
NC
Supply Input for Control Circuit. This pin provides bias voltage to the control circuitry and
driver for the pass transistor.The driving capability of output current is proportioned to the VCNTL.
For the device to regulate, the voltage on this pin must be at least 1.5V greater than the output
voltage, and no less than VCNTL_MIN.
Not Internally Connected.
Output Voltage. This pin is power output of the device. A pull low resistance exists when the
VOUT
device is disabled by pulling low the EN pin. To maintain adequate transient response to large
load change, typical value of 1000uF Al electrolytic capacitor with 10uF ceramic capacitors are
recommended to reduce the effects of current transients on VOUT.
FB
GND
Feedback Voltage. This pin is the inverting input to the error amplifier. A resistor divider from
the output to GND is used to set the regulation voltage as VOUT = 0.8x(R1+R2)/R1 (V)
Ground.
GND
Ground. The exposed pad acts the dominant power dissipation path and should be soldered
to well design PCB pads as described in the Application Informations Chapter.
Functional Block Diagram
EN
CNTL
VIN
2 43
www.DataSheet4U.com
Thermal Limit
0.3V
Softstart &
Control Logic
Power On
Reset
Current Limit
FB 7
0.8V VREF
6
92% VREF
Delay
1
POK
8
GND
uPI Semiconductor Corp., http://www.upi-semi.com
Rev. F00, File Name: uP7706-DS-F0000
2
|