Datasheet

UNISONIC TECHNOLOGIES CO., LTD
P1595
LINEAR INTEGRATED CIRCUIT
200KHZ, 1.5A PWM BUCK
DC/DC CONVERTER

DESCRIPTION
The UTC P1595 is a monolithic integrated circuit intended for the
use of a step-down DC/DC converter and it can drive a 1.5A load
without additional transistors.
The internal compensation makes feedback control having good
line and load regulation without external design. The external
shutdown function can be controlled by logic level and then enter the
standby mode.
The UTC P1595 features a guaranteed +3% tolerance on
output voltage under specified input voltage and output load
conditions. Thermal shutdown protection is designed to prevent over
temperature operating from damage while current limit protection is
against over current operating of the output switch. The switching
frequency will be reduced if current limit function occurs and feedback
voltage (VFB) drops below 0.5V. The UTC P1595 works at a 200kHz
switching frequency so it allows smaller sized filter components.

FEATURES
* Output Voltage In Adjustable Output Version.
* Adjustable Version Output Voltage Range: 0.75V ~ 22V With+3%
Accuracy.
* Short Circuit Protect
* Fixed Switching Frequency: 200KHZ.
* On/Off Shutdown Control Input.
* Voltage Mode Non-Synchronous Pulse Width Modulation (PWM)
Control.
* Thermal-Shutdown And Current-Limit Protection.
* Operating Voltage Can Be Up To 24V.
* 1.5A Output Load Current.
* Low Power Standby Mode.
* Built-In Switching Transistor

ORDERING INFORMATION
Ordering Number
P1595G-AB5-R
Package
SOT-89-5
Packing
Tape Reel
P1595G-AB5-R
(1)Packing Type
(1) R: Tape Reel
(2)Package Type
(2) AB5: SOT-89-5
(3)Green Package
(3) G: Halogen Free and Lead Free
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P1595
LINEAR INTEGRATED CIRCUIT

MARKING

PIN CONFIGURATION


VCC
EN
5
4
1
2
3
SW
GND
FB
PIN DESCRIPTION
PIN NO.
PIN NAME
1
2
3
4
5
SW
GND
FB
EN
VCC
DESCRIPTION
Switching Output
Ground
Feedback Voltage
On/Off Pin
Operating Voltage Input
BLOCK DIAGRAM
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
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING (unless otherwise specified)
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Voltage
VCC
+26
V
ON/OFF Pin Input Voltage
VEN
-0.3 ~ VCC
V
Feedback Pin Voltage
VFB
-0.3 ~ 12
V
Operating Supply Voltage
VOP
4.5~24
V
Output Voltage to Ground
VOUT
-0.8
V
Power Dissipation (Note 1)
TA=25°C
PD
690
mW
Operating Temperature
TOPR
-20 ~ +125
°C
Storage Temperature
TSTG
-65 ~ +150
°C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

THERMAL DATA
PARAMETER
SYMBOL
RATINGS
UNIT
Junction to Ambient (Note 1)
θJA
180
°C/W
Junction to Case (Note 1)
θJC
38
°C/W
Note: 1. It’s Measured with the PCB copper area (need connect to VSS pins) of approximately 1.5 in2(Multi-layer)

ELECTRICAL CHARACTERISTICS (TA=25°C, VCC=12V, ILOAD=0.2A, unless otherwise specified)
PARAMETER
Feedback Voltage
Saturation Voltage
Quiescent Current
Feedback Bias Current
Shutdown Supply Current
Current Limit
SW Pin Leakage
Current
SW pin=0V
SW pin=-0.8V
Oscillator Frequency
Oscillator Frequency Circuit Protect
of Short
Max. Duty Cycle (ON)
Min. Duty Cycle (OFF)
EN Pin Logic Input Threshold
Voltage
EN pin Logic Input Current
EN pin Input Current
Thermal Shutdown Temp
SYMBOL
TEST CONDITIONS
VFB
IOUT=0.2A
IOUT=1.5A, No outside circuit
VSAT
VFB=0V force driver on
IQ
VFB=1.2V force driver off
IFB
IOUT=0.1A
ISD
VEN=0V
Pear current, No outside circuit
I(LIMIT)
VFB=0V force driver on
No outside circuit
ISW(LEAK) VFB=1.0V force driver off
VCC=24V force driver off
FOSC
FSCP
DC
VIH
VIL
IH
IL
TSD
TYP
0.750
MAX
0.773
UNIT
V
1.2
1.5
V
4
-10
2
8
-50
10
mA
nA
μA
1.8
140
A
-5
200
-50
μA
260
mA
KHz
(Adjustable) When VFB<0.5V
80
KHz
VFB=1.2V force driver off
VFB=0V force driver on
High (regulator ON)
Low (regulator OFF)
VEN=2.5V (ON)
VEN=0.3V (OFF)
0
100
1.2
1.2
20
-5
135
%
%
V
V
μA
μA
°C
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MIN
0.728
0.5
2.0
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TYPICAL APPLICATION CIRCUIT
Adjustable Output Voltage Version
R1 

VOUT=VFB× 1 
 , VFB=0.75V. R2=0.75K~4K
 R2 
Resistor select for output voltage setting
VOUT
5V
3.3V
2.5V
1.8V
1.5V
1.3V
1.2V
R2
1.2K
2K
2K
2K
2K
2K
2K
L1 recommend value (VIN=12V, IOUT=1.5A,)
VOUT
1.8 V
L1 Value
22μH
2.5V
22μH

R1
6.8K
6.8K
4.7K
3K
2K
1.5K
1.2K
3.3V
33μH
5V
33μH
FUNCTION DESCRIPTIONS
Pin Functions
VCC
It provides the IC switching regulator with positive input supply. This pin is used to supply the switching currents
needed by the regulator and a suitable input bypass capacitor must be connected at this pin.
GND
Circuit ground.
SW
Internal switch. The voltage at this pin switches between (+VCC-VSAT) and approximately-0.5V, with a duty cycle of
approximately VOUT / VCC. To minimize coupling to sensitive circuitry, you should minimize the PC board copper area
connected to this pin.
Feedback
Senses the regulated output voltage to complete the feedback loop.
EN
Using logic level signals to allow the switching regulator circuit to be shutdown, which dropping the total input
supply current to approximately 10uA. Shut the regulator down through pulling this pin below a threshold voltage of
approximately 0.5V, turn the regulator on through pulling this pin above 2.0V (up to VCC MAX).
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LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS
VOUT
2V/div
VCC/EN
5V/div
VCC/EN
5V/div
VOUT
2V/div
1. Startup during power on
2. Low-frequency triangle wave control enable pin
2V/div
1V/div
VCC=24V
1V
0
2V
0
0
2500
Time (500ms/div)
5000
EN
1V/div
EN
1V/div
VOUT
2V/div
VOUT
2V/div
3. Control enable pin with power supply to normal
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TYPICAL CHARACTERISTICS(Cont.)
4. Transient response with step load
VCC=24V
50mV
50mV/div
50mV/div
VCC=12V
0
-50mV
50mV
0
-50mV
0
1000
Time (200µs/div)
2000
0
500
Time (100µs/div)
1000
Efficiency (100%)
5. Efficiency
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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