Datasheet

UNISONIC TECHNOLOGIES CO., LTD
P1686
LINEAR INTEGRATED CIRCUIT
600KHZ, 3A STEP-DOWN
CURRENT MDOE SWITCHING
REGULATOR
„
DESCRIPTION
As a current mode switching regulator with an integrated
switch, the UTC P1686 is operating at 600kHz with separate sync
and enable functions. In order to avoid frequency beating in noise
sensitive applications the sync function allows customers to
synchronize to a faster clock. Cost effective low power solutions
is considered in the integrated switch ,and so peak switch current
3 amps. Very small passive components is considered in High
frequency of operation. Current mode operation: fast dynamic
response and instantaneous duty cycle adjustment as the input
changes, as a ideal for CPE applications where the input is a wall
plug power.
The low shutdown current as ideal for portable applications
when battery life is important.
The UTC P1686 is synchronizable to a frequency from 750kHz
to 1.2MHz.
„
FEATURES
* Integrated 3 Amp switch
* 600kHz frequency of operation
* Current mode controller
* Synchronizable to higher frequency up to 1.2MHz
* 6μA low shutdown current
„
ORDERING INFORMATION
Ordering Number
Normal
Lead Free Plating
P1686-S08-R
P1686L-S08-R
P1686-S08-T
P1686L-S08-T
P1686-SH2-R
P1686L-SH2-R
P1686-SH2-T
P1686L-SH2-T
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Copyright © 2008 Unisonic Technologies Co., Ltd
Package
Packing
SOP-8
SOP-8
HSOP-8
HSOP-8
Tape Reel
Tube
Tape Reel
Tube
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P1686
LINEAR INTEGRATED CIRCUIT
PIN CONFIGURATION
„
SOP-8
HSOP-8
BST 1
8
SYNC
IN 2
7
EN
SW 3
6
COMP
GND 4
5
FB
BST 1
IN 2
SW 3
GND 4
GND
8
SYNC
7
EN
6
COMP
5
FB
PIN DESCRIPTION
„
PIN NO.
PIN NAME
1
BST
2
IN
3
SW
4
GND
5
FB
6
COMP
7
EN
8
SYNC
PIN FUNCTION
Providing power to the internal NPN switch. To turn on for this switch the lowest voltage is
2.7V.
This PIN delivers all control and power circuitry’s power, and sees high di/dt during
switching. A decoupling capacitor is better to be attached to this pin very closely.
This PIN is the emitter of the internal switch and should be connected with the external
freewheeling diode very closely.
Almost all voltages are measured with respect to this pin. The decoupling capacitor and the
freewheeling diode is better to be connected to this PIN as short as possible.
Input of feedback for adjustable output controllers.
Output of the internal error amplifier and also input of the peak current comparator. To
achieve the specified performance a compensation network is connected to this pin.
Chip enable input. EN is high: the regulator switched on; EN is low: off. EN is low: the
regulator is in standby mode, and the input supply current is reduced to a few
microamperes.
Synchronous control pin used to synchronize the internal oscillator to an external pulse
control signal. But it should be connected to GND when not used.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R103-039.C
P1686
BLOCK DIAGRAM
COMP 6
ISEN
40m
SLOPE
+
2 IN
+
IS
+
„
LINEAR INTEGRATED CIRCUIT
+
-
FB 5
PWM
EA
1 BS
IS
1V
EN 7
REFERENCE
UVLO
SOFT START
HICCUP OL
0.7V
S
Q
R
POWER
TRANSISTOR
FB
3 SW
SLOPE
SYNC 8
OSCILLATOR
SLOPE COMP
FREQUENCY
CLK
4 GND
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www.unisonic.com.tw
3 of 6
QW-R103-039.C
P1686
„
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
RATINGS
UNITS
Input Supply Voltage
VIN
-0.3 ~ +28
V
Boost Pin Above VSW
(VBST -VSW)
16
V
Boost Pin Voltage
VBST
-0.3 ~ +32
V
EN Pin Voltage
VEN
-0.3 ~ +16
V
FB Pin Voltage
VFB
-0.3 ~ +6
V
FB Pin Current
IFB
1
mA
SYNC Pin Current
ISYNC
1
mA
Junction Temperature
TJ
150
°C
Operating Temperature
TOPR
-40 ~ +85
°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
Junction to Ambient
SYMBOL
θJA
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
RATINGS
36.5
UNITS
°C/W
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P1686
„
LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS
(VIN = 12V, VCOMP = 0.8V, VBS = VIN + 5V, EN = tied to VIN, SYNC = 0, SW = open. TA = TJ = -40°C ~ 85°C.)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN TYP MAX UNITS
Operating Input Voltage (Note 1)
VIN
16
V
Maximum Switch Current Limit
ISW
3.0
A
Oscillator Frequency
fOSC
550 600
750
kHz
Switch On Voltage Drop
VD(SW) ISW = 3A
330
mV
VIN Undervoltage Lockout
VUVLO TA = 25°C
2.60
3
V
VIN Supply Current
IQ
VFB = VOUT(NOM) + 17%
1.0
5
mA
VEN = 0V, VIN = VBOOST = 16V,
5
45
μA
Standby Current
IQ(OFF)
VSW = 0V
FB Input Current
IFB
-0.25 -0.50
μA
Feedback Voltage
1.176 1.2 1.224
V
Feedback Voltage Line Regulation
3V < VIN < 16V (Note 2)
+3
mV/V
FB to VCOMP Voltage Gain (Note 3)
0.4V ≤ VCOMP ≤ 0.9V
150 350
FB to VCOMP Transconductance (Note 3)
Δ ICOMP = ± 10μA
500 850 1300 μMho
VCOMP Pin Source Current
VFB = VOUT(NOM) -17%
70
110
μA
VCOMP Pin Sink Current
VFB = VOUT(NOM) + 17%
70
110
μA
VCOMP Pin to Switch Current Trans
2.5
A/V
conductance
VCOMP Pin Maximum Switching
Duty cycle = 0%
0.35
V
Threshold
VCOMP Pin Threshold
ISW = 3A
0.9
V
Maximum Switch Duty Cycle
VCOMP = 1.2V, ISW = 400mA
85
%
Minimum Boost Voltage Above Switch
ISW = 3A, 0°C ≤ TA ≤ 85°C
VBOOST
1.8
2.7
V
(Note 3)
ISW =2.5A, TA < 0°C
ISW = 1A
10
15
Boost Current
IBOOST ISW = 3A, 0°C ≤ TA ≤ 85°C
mA
30
45
ISW =2.5A, TA < 0°C
3
V
VIH
Enable Input Threshold Voltage
VIL
0.4
V
EN = 60mV above threshold
2.5
μA
IIL
Enable Input Bias Current
IIH
EN = 100mV below threshold
5
15
μA
SYNC Threshold Voltage
1.5
V
SYNC Input Frequency (Note 4)
750
1200 kHz
SYNC Pin Resistance
VSYNC = 0.5V
20
kΩ
Note: 1. The device may not function properly outside its operating input voltage range.
2. The required minimum input voltage for a regulated output depends on the output voltage and load
condition.
3. Guaranteed by design.
4. For SYNC applications, please contact factory.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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P1686
LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATION CIRCUIT
„
APPLICATION CIRCUIT
D1
„
Design Example: 16V to 5V at 2A
C1
0.22u
1
2
VIN=16V
C3
10u
BS
IN
R4
4.75K
3
SW
D3
VO=5V
R1
31.6k
UTC P1686
7
8
FB
EN
SYNC
L1
8.2uH
C2
10u
5
D2
6
COMP
GND
4
C4
3.3n
C5
180p
R2
10k
R3
3.4k
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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QW-R103-039.C
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