Ordering number : EN5920A
Monolithic Linear IC
LA7995M
Charge Pump Type DC-DC Converter
Overview
This DC-DC converter IC supplies 30V from a V
CC
of
5V. Possible applications include use as a power
supply for tuner circuitry on a PC video board.
Conventional DC-DC converters utilize the
counterelectromotive force in a coil to step up the
voltage. This method suffers from high-frequency
noise caused by sharp pulses. The so-called charge
pump principle adopted in the LA7995M chip results in
much lower noise and also has the advantage of using
only capacitors, reducing the cost for peripheral
components.
Package Dimensions
unit:mm
3111-MFP14S
[LA7955M]
8
0.625
0.1
1.5
1.8max
0.15
14
1
8.0
7
0.35
1.0 1.0
SANYO:MFP14S
Specifications
Maximum Ratings
at Ta = 25
°
C
Parameter
Maximum supply voltage
Allowable power dissipation
Operating temperature
Storage temperature
Symbol
V
CC
max
Pd max
Topr
Tstg
Ta
≦
65°C*
Conditions
Ratings
7
380
–10 to +65
–55 to +150
Unit
V
mW
°C
°C
Note: *Includes substrate (phenol) 144.3
x
76.1 x 1.6 mm
Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability，such as life-support systems，aircraft’
s
control systems，or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.
SANYO 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， other
or
parameters) listed in products specifications of any and all SANYO products described or contained
herein.
SANYO Electric Co., Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
71598RM(KI) No. 5920-1/5
5.15
6.4
4.4
LA7995M
Operating Conditions
at Ta = 25
°
C
Parameter
Recommended supply voltage
Operating supply voltage range
Symbol
V
CC
V
CC
op
Conditions
Ratings
5
4.75 to 5.25
Unit
V
V
Operating Characteristics
at Ta = 25
°
C
Parameter
Current drain
Output voltage
Output voltage fluctuation
Output current
Oscillation frequency
Symbol
I
IN
V
OUT
△V
OUT
I
OUT
f
I
O
=1 mA, V
CC
=5V
I
O
=1 mA, V
CC
=5V
I
O
=1 mA, V
IN
=4.75 to 5.25V
V
O
=29V
C
OSC
=150pF
1.5
35
Conditions
min
19
29
Ratings
typ
24
30.7
1.0
1.7
50
65
max
29
32
1.5
Unit
mA
V
V
mA
KHz
Note: The above specifications are measured with external capacitance provided by three 0.33
µF
chip capacitors(C1,
C2, C3).
Charge Pump Principle
Figure 1 shows a charge pump circuit. Driving S1 and S2 with opposite phase produces a doubled voltage
VOUT≒2VCC
S1
VCC
S2
A11009
Figrue 1 Chrage pump circuit
In order to supply 30V from 5V, the LA7995M uses three charge pump circuits in series to produce a step-up factor of 2
x 2 x 2 = 8.
71598RM(KI) No. 5920-2/5
LA7995M
Block Diagram
The LA7995M incorporates the following functions for controlling the 3-stage charge pump circuit:
• Oscillator
• Switching circuit
VCC=5V
＋
Cvcc2
Cvcc1
C3
Cosc
14
13
12
NC
11
NC
10
NC
9
8
Oscillator
Switching
circuit
30V zener
diode circuit
D1
Charge pump
1
Charge pump
2
Charge pump
3
1
2
3
4
5
6
7
C1
C2
Creg
＋
Cout
＋
A11010
Figure 2 Block diagram
Equivalent Internal Circuit and Recommended Peripheral Circuitry
VCC=5V
＋
47μF
0.01μF
Charge：6μA
Discharge：200μA
0.33μF
150pF
14
13
12
NC
11
NC
10
NC
9
8
6μA
1kΩ
1kΩ
100μA
200μA
VCC
200Ω
7.5kΩ
1kΩ
1
2
3
4
5
6
7
0.33μF
0.33μF
＋
＋
4.7μF
4.7μF
Vout=30V
A11011
71598RM(KI) No. 5920-3/5
LA7995M
Test Circuit
V-14
＋
47μF
10nF
150pF
14
13
12
NC
11
NC
10
NC
9
＋
0.33μF
8
Oscillator
Switching
circuit
30V zener
diode circuit
D1
Charge pump
1
Charge pump
2
Charge pump
3
1
＋
2
3
4
＋
5
6
7
0.33μF
0.33μF
＋
＋
R-1
4.7μF
4.7μF
V-7
A11012
Test Method
Item
Current consumption
Symbol
I
IN
Measurement
point
V-14
Output current (mA)
Test method
Connect a DC current generator to V-7 and use an
ammeter to measure the current supplied to V-14 when
1mA is drawn from V-7.
Output voltage
Output voltage fluctuation
V
OUT
△V
OUT
I
OUT
f
V-7
V-7
V-7
R-1
Mesure voltage at V-7.
Vary power supply voltage from 4.75 to 5.25V. Measure
voltage change at V-7.
Output current
Oscillation frequency
Measure output current required to obtain 29V from V-7.
Measure frequency of pulse wave form at R-1.
-
1.0
1.0
1.0
V-7
1.0
71598RM(KI) No. 5920-4/5
LA7995M
Specifications of any and all SANYO products described or contained herein stipulate the performance，
characteristics，and functions of the described products in the independent state，and are not guarantees
of the performance，characteristics，and functions of the described products as mounted in the customer's
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device，
the customer should always evaluate and test devices mounted in the customer's products or equipment.
SANYO Electric Co.，Ltd. strives to supply high-quality high-reliability products. However，any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives，that could give rise to smoke or fire，
or that could cause damage to other property. When designing equipment，adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design，redundant design，and structural design.
In the event that any and all SANYO products described or contained herein fall under strategic
products (including services) controlled under the Foreign Exchange and Foreign Trade Control Law of
Japan，such products must not be exported without obtaining export license from the Ministry of
International Trade and Industry in accordance with the above law.
No part of this publication may be reproduced or transmitted in any form or by any means，electronic or
mechanical，including photocopying and recording，or any information storage or retrieval system，
or otherwise，without the prior written permission of SANYO Electric Co.
，Ltd.
Any and all information described or contained herein are subject to change without notice due to
product/technology improvement，etc. When designing equipment，refer to the“Delivery Specification”
for the SANYO product that you intend to use.
Information (including circuit diagrams and circuit parameters) herein is for example only；it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable，but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.
This catalog provides information as of July, 1998. Specifications and information herein are subject to change
without notice.
PS
71598RM(KI) No. 5920-5/5
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