Datasheet

UNISONIC TECHNOLOGIES CO., LTD
P2680
Preliminary
CMOS IC
WIDE INPUT 2A
SYNCHRONOUS RECTIFIED
STEP-DOWN CONVERTER

DESCRIPTION
The UTC P2680 is a monolithic synchronous step-down, fixed
340kHz frequency, current-mode, PWM controller with an internal
power MOSFET. It achieves 2A continuous output current over a
wide input supply range from 4V to 26V with excellent load and line
regulation. Equipped with an external compensation pin, this device
offers user flexibility in determining loop dynamic.
Current mode control provides fast transient response and
cycle-by-cycle current limit. A PWM control circuit can provide the
duty ratio from 0 up to 90% linearly. An Under-Voltage-Lock-Output
(UVLO) circuit monitors the VIN supply voltage to prevent wrong
logic controls. Additional under voltage protections monitor the
voltage on FB pin for short-circuit protections.
In application, the UTC P2680 is suitable for portable devices
when it works as an ideal power supply in SOP-8L package.

HSOP-8
FEATURES
* 2A Output Current
*340KHz frequency of operation
* 4V~26V Input Voltage Range
* 20μA Shutdown Supply Current
* Output Adjustable
* Frequency FoldBack at Short Circuit
* VIN Under-voltage Lockout
* Thermal Shutdown
* OCP
* Programmable Soft-Start
* Up to 90% Efficiency

ORDERING INFORMATION
Ordering Number
Lead Free
P2680L-SH2-R
P2680L-SH2-R
Halogen Free
P2680G-SH2-R
Package
Packing
HSOP-8
Tape Reel
(1)Packing Type
(1) R: Tape Reel
(2)Package Type
(2) SH2: HSOP-8
(3)Lead Free
(3) L: Lead Free, G: Halogen Free
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Copyright © 2014 Unisonic Technologies Co., Ltd
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P2680

Preliminary
CMOS IC
MARKING INFORMATION
PACKAGE
MARKING
HSOP-8


PIN CONFIGURATION
BST
1
8
SS
VIN
2
7
EN
SW
3
6
COMP
GND
4
5
FB
PIN DESCRIPTION
PIN NO.
1
2
3
4
5
6
7
PIN NAME
BST
VIN
SW
GND
FB
COMP
EN
8
SS
DESCRIPTION
Bootstrap pin. Positive supply for the upper MOSFET driver.
Power supply pin.
Power switch output pin.
Ground pin.
The output voltage feedback pin. It is also the inverting input of the error amplifier.
Compensation pin. It is also the output of the internal error amplifier.
Enable Input. A high input at EN turns on the converter, and a low input turns it off.
Soft-Start pin. Connect a capacitor from SS to GND to set the soft-start period. To
disable the soft-start feature, leave SS unconnected.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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P2680

Preliminary
CMOS IC
BLOCK DIAGRAM
VIN
Reference
Voltage Source
and Bias Current
Source
EN
+
UVLO
+
+
Current
Limit
Slope
BST
NMOS
S
Q
0.923V
+
SS
+ EA
FB
-
COMP
R
+
-
Driver
PWM
OTP
SW
6
100kHz-340kHz
Oscillator
NMOS
Short Circuit Signal
GND
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P2680

Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
VIN Supply Voltage
VIN
26
V
SW Voltage
VSW
-1~VIN+1
V
BST Voltage
VBST
VSW-0.3~VSW+8
V
EN Voltage
VEN
-0.3~6
V
FB Voltage
VFB
-0.3~6
V
COMP Voltage
VCOMP
-0.3~6
V
Maximum Power Dissipation
PD
0.76
W
Junction Temperature
TJ
-40~150
°C
Storage Temperature
TSTG
-55~150
°C
Notes: 1. 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.
2. Exceeding these ratings may damage the device.

RECOMMENDED OPERATING CONDITIONS (Note)
PARAMETER
SYMBOL
Input Voltage
VIN
Ambient Operating Temperature
TA
Note: The device is not guaranteed to function outside its operating rating.
RATINGS
4~26
-40 ~ +125
UNIT
V
°C
PARAMETER
SYMBOL
RATINGS
Junction to Ambient
θJA
105
Junction to Case
θJC
50
Note: Measured on approximately 1” square of 1 oz. Copper surrounding device leads.
UNIT
°C/W
°C/W


PACKAGE THERMAL CHARACTERISTICS (Note)
ELECTRICAL CHARACTERISTICS (TA = 25°C, VIN = 12V, unless otherwise specified.)
PARAMETER
Input Voltage
Feedback Voltage
Switch On Resistance (High-Side)
Switch On Resistance (Low-Side)
SW Leakage
Current Limit
Current Limit Gain.
Output Current to Comp Pin Voltage
Error Amplifier Transconductance
Error Amplifier Gain
Oscillator Frequency
Short Circuit Frequency
Maximum Duty Cycle
Minimum Duty Cycle
Enable Threshold Voltage
Enable Pull-Up Current
Supply Current in Shutdown
IC Supply Current in Operation
Soft-Start Current
Soft-Start Period
Thermal Shutdown Temperature
SYMBOL
TEST CONDITIONS
VIN
VOUT= 5V, ILOAD = 0A~1A
VFB
4.5V ≤ VIN ≤ 23V, VCOMP< 2V
RONH
RONL
VEN= 0V
ILIM
UNIT
V
V
Ω
Ω
µA
A
3.3
A/V
600
8000
340
100
90
µA/V
V/V
kHz
kHz
%
%
V
µA
µA
mA
µA
ms
°C
∆ICOMP= ±10µA
FOSC
FOSC_S
DMAX
DMIN
VEN
IEN
ISD
IO
T
305
VFB= 0V
VFB= 0.7V
VFB= 1.1V
Hysteresis = 0.2V
VEN = 0V
VEN = 0V
VEN>2V, VFB= 1.4V
VSS = 0V
CSS = 0.1μF
Hysteresis = 10°C
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP MAX
7
26
0.900 0.923 0.946
0.20
0.20
0
8
2.4
375
0
1
4.8
110
0.9
6
15
160
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P2680

Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT
Figure 1. Shows an example UTC P2680 application circuit generating a 2.5V/2A output.
CB 10nF
BST
VIN
VIN
EN
ON/OFF
SS
CIN
10µF/35V
+
L1 10µH/3A
UTC
GND
CSS
0.1µF
2.5V/2A
SW
RF1
12k
COMP
VOUT
FB
CC1
2.2nF
RC1
8.2k
CC2
(Optional)
RF2
13k
COUT
22µF/10V
Ceramic, or
47µF/6.3 SP
Cap
Typical Compensation for Different Output Voltages and Output Capacitors
VOUT
COUT
2.5V
22μF Ceramic
3.3V
22μF Ceramic
5V
22μF Ceramic
2.5V
47μF SP CAP
3.3V
47μF SP CAP
5V
47μF SP CAP
2.5V
470μF/6.3V/30mΩ
3.3V
470μF/6.3V/30mΩ
5V
470μF/6.3V/30mΩ
Note: CC2 is needed for high ESR output capacitor.
RC1
8.2kΩ
12kΩ
15kΩ
15kΩ
15kΩ
15kΩ
15kΩ
15kΩ
15kΩ
CC1
2.2nF
1.5nF
1.5nF
1.5nF
1.8nF
2.7nF
15nF
22nF
27nF
CC2 (Note )
None
None
None
None
None
None
1nF
1nF
None
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.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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