SM6702-27HA [NPC]
PFM Step-up DC/DC Converter; PFM升压DC / DC转换器型号: | SM6702-27HA |
厂家: | NIPPON PRECISION CIRCUITS INC |
描述: | PFM Step-up DC/DC Converter |
文件: | 总10页 (文件大小:116K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
SM6702 series
PFM Step-up DC/DC Converter
NIPPON PRECISION CIRCUITS INC.
OVERVIEW
The SM6702 series are step-up DC/DC converter ICs, fabricated using NPC’s Molybdenum-gate CMOS pro-
cess. They incorporate reference voltage source, error amplifier, oscillator, start-up circuit, PFM (Pulse Fre-
quency Modulation) control circuit into a single chip. The only external components required are a Coil, Diode
and output smoothing capacitors to form a step-up DC/DC converter. They employ PFM voltage control cir-
cuits to achieve high efficiency, stable constant-voltage output.
FEATURES
ꢀ Power dissipation : 24 µW at V = 1.5 V, V
= 3.0 V, I
= 100 µA
IN
OUT
OUT
ꢀ Start-up input voltage : 0.9 V (max) at R = 30 kΩ
L
ꢀ Output voltage : 2.2 V to 3.3 V, available in 0.1 Vstep
ꢀ High efficiency : 85% at V = 1.5 V, V
= 3.0 V, I = 1 mA
IN
OUT
OUT
ꢀ Low ripple voltage
ꢀ Package : SOT23-3, SOT89-3
APPLICATIONS
ꢀ PDA, Mobile IT equipment
ꢀ Digital Stil Camera
ꢀ Pager
ꢀ Constant-voltage sources for battery-operated equipment
ꢀ Local voltage sources
ORDERING INFORMATION
1
De vice
Output voltag e
3.3 V
Packag e
S OT89-3
S OT23-3
S OT89-3
S OT23-3
S OT89-3
S OT23-3
SM6702-33HB
SM6702-30HA
SM6702-30HB
SM6702-27HA
SM6702-27HB
SM6702-24HA
3.0 V
3.0 V
2.7 V
2.7 V
2.4 V
1. Stepwise setting with a step of 0.1V in the range of 2.2V to 3.3V is available.
NIPPON PRECISION CIRCUITS—1
SM6702 s eries
PINOUT
(Top view)
SM6702−××HA(SOT23−3)
SM6702−××HB(SOT89−3)
3
2
1
2
1
2
3
PIN DESCRIPTION
Nu mb e r
Na me
Des cription
SM6702−××HA
SM6702−××HB
1
2
3
1
3
2
VS S
LX
Ground
Switching pin
OUT
Output (device supply pin)
PACKAGE DIMENSIONS
(Unit : mm)
SM6702−××HA(SOT23−3)
SM6702−××HB(SOT89−3)
4.5 0.1
1.5 0.1
0.4 0.1
0 to 15
2.9 0.2
1.55 0.15
0.1 0.05
0.95 0.95
1.5
1.5
0.37 0.1
(8 )
(8 )
0.4 0.1
M
0.2
0.42 0.1
0.42 0.1
0.47 0.1
NIPPON PRECISION CIRCUITS—2
SM6702 s eries
BLOCK DIAGRAM
OUT
LX
PFM OSC
START−UP
VREF
VSS
NIPPON PRECISION CIRCUITS—3
SM6702 s eries
SPECIFICATIONS
Absolute Maximum Ratings
T = 25 °C
a
Parameter
LX impressed voltage
OUT impressed voltage
LX output current
Symbol
Condition
Rating
5
Unit
V
V
LX
V
4
V
OUT
I
200
mA
LX
SM6702−××HA
SM6702−××HB
150
Power dissipation
P
m W
D
500
Operating temperature
Storage temperature
T
−
20 to 70
°
°
C
C
opr
T
− 40 to 125
stg
Electrical Characteristics
L = 330 µH, C = 22 µF, T = 25 °C, V = 0 V
a
SS
Rating
Parameter
Symbol
Condition
Unit
min
typ
–
ma x
0.9
0.7
16
Start-up voltage
V
st
R
R
V
= 30 kΩ
–
–
–
V
V
L
Holding voltage
V
= 3 kΩ
–
hold
L
Current consumption
I
= 1.5 V, R = 30 kΩ
8
µA
S S
IN
L
V
0.975
×
V
1.025
×
target
target
Output voltage
V
V
= 1.5 V, R = 3 kΩ
V
V
OUT
IN
L
target
2.2
2.8
≤
≤
V
V
≤
≤
2.7
3.3
60
–
–
–
–
target
V
= V
= 0.4 V
− 0.1,
OUT
target
LX output current
I
mA
LX
V
LX
80
target
LX leakage current
I
V
= V = 3.5 V
–
–
1
µA
kHz
%
LXL
OUT
LX
Maximum oscillator frequency
Switch ON duty cycle
f
V
= V
−
−
0.1
0.1
80
100
75
120
85
OS C
OUT
target
target
Duty
V
= V
65
OUT
V
+
target
0.2
Input voltage range
V
–
–
V
IN
V
: Setting output voltage
target
NIPPON PRECISION CIRCUITS—4
SM6702 s eries
FUNCTIONAL DESCRIPTION
Step-up Principle
The SM6702 series use a transistor to switch the input supply in a non-isolated chopper switching regulator
configuration. The figure below shows the basic step-up switching regulator circuit.
If the transistor is ON for an interval t and then instantly turned OFF, the energy stored in the coil L during
ON
the interval t generates a voltage V across the coil. This voltage is superimposed on the input voltage such
ON
L
that the peak voltage reaches V + V which forces the diode D to conduct and release the stored energy into
IN
L
the output.
During normal operation, the above switching occurs repeatedly at a frequency controlled by an oscillator
(which can change depending on the input and output load conditions), generating a square wave output which
is then smoothed by the output capacitor C. Thus the output voltage (V
> V ) has been stepped up.
OUT
IN
L
D
VIN
VOUT
Tr
C
GND
PFM Control
In SM6702 series, the LX transistor ON interval is fixed, and the OFF interval varies in response to the input
voltage and load changes. Thus the resulting switching cycle frequency varies, called pulse frequency modula-
tion.
NIPPON PRECISION CIRCUITS—5
SM6702 s eries
BASIC CIRCUIT
L
D
VIN
OUT
+
C
LX
OUT
VSS
Coil (L) : 330 µH
Diode (D) : MA721 (Matsushita Schottky diode)
Capacitor (C ) : 22 µF tantalum
L
TYPICAL APPLICATION CIRCUIT
L
D
3V System
Voltage
+
+
LX
OUT
C1
C2
C3
1.5V
VSS
Coil (L) : 330 µH
Schottky Diode (D)
Capacitor (C1) : 22 µF tantalum
Capacitor (C2) : 0.22 µF ceramic
Capacitor (C3) : 22 µF tantalum
NIPPON PRECISION CIRCUITS—6
SM6702 s eries
BASIC CHARACTERISTICS
SM6702-30HA (V : 3.0V)
out
Output voltage vs. Output current
L=470µH, C=22µF
L=330µH, C=22µF
3.5
3
3.5
V
in=1.5V
Vin=1.5V
3
2.5
2
V
in=0.9V
Vin=0.9V
2.5
2
Vin=1.2V
V
in=1.2V
1.5
1
1.5
1
0.5
0
0.5
0
0
5
10
15
20
25
30
0
5
10
15
20
25
30
Output Current Iout[mA]
Output Current Iout[mA]
Efficiency vs. Output current
L=470µH, C=22µF
L=330µH, C=22µF
100
100
95
90
85
80
75
70
65
60
55
50
95
90
85
80
Vin=0.9V
Vin=0.9V
V
in=1.5V
75
70
65
60
55
50
Vin=1.5V
V
in=1.2V
Vin=1.2V
0
5
10
15
20
25
30
0
5
10
15
20
25
30
Output Current Iout[mA]
Output Current Iout[mA]
Ripple voltage vs. Output current
L=330µH, C=22µF
200
175
150
125
Vin=1.5V
100
Vin=1.2V
75
50
25
0
Vin=0.9V
20
0
10
30
40
50
60
Output Current Iout[mA]
NIPPON PRECISION CIRCUITS—7
SM6702 s eries
Output voltage vs.Temperature
Maximum oscillator frequency vs.
Temperature
Vin=1.5V, L=330µH, RL=3kΩ
Vout=2.9V
3.2
200
175
150
125
3.1
3.0
2.9
2.8
100
75
50
25
0
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
Temperature [°C]
Temperature [°C]
Start-up voltage vs.Temperature
Hold-on voltage vs.Temperature
L=330µH, RL=30kΩ
L=330µH, RL=3kΩ
1.0
1.0
0.8
0.6
0.4
0.2
0.0
0.8
0.6
0.4
0.2
0.0
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
Temperature [°C]
Temperature [°C]
Current consumption vs.Temperature
Oscillator duty cycle vs.Temperature
Vin=1.5V, L=330µH, RL=30kΩ
Vout=2.9V
10
90
85
80
75
70
65
60
55
50
8
6
4
2
0
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
Temperature [°C]
Temperature [°C]
NIPPON PRECISION CIRCUITS—8
SM6702 s eries
LX switching current vs.Temperature
LX leakage current vs.Temperature
Vin=Vout=3.5V
Vout=2.9V
200
100
10
1
175
150
125
100
75
50
25
0
0.1
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
Temperature [°C]
Temperature [°C]
NIPPON PRECISION CIRCUITS—9
SM6702 s eries
NIPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to
improve the design or performance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility for
the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits
are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision
Circuits Inc. makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification.
The products described in this data sheet are not intended to use for the apparatus which influence human lives due to the failure or
malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter,
including compliance with export controls on the distribution or dissemination of the products. Customers shall not export, directly or
indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies.
NIPPON PRECISION CIRCUITS INC.
4-3, Fukuzumi 2-chome
Koto-ku, Tokyo 135-8430, Japan
Telephone: +81-3-3642-6661
Facsimile: +81-3-3642-6698
http://www.npc.co.jp/
NIPPON PRECISION CIRCUITS INC.
Email: sales@ npc.co.jp
NC9721CE 2000.10
NIPPON PRECISION CIRCUITS—10
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