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GS7660ISのメーカーはVishay Siliconixです、この部品の機能は「Switched-Capacitor Voltage Converter」です。 |
部品番号 | GS7660IS |
| |
部品説明 | Switched-Capacitor Voltage Converter | ||
メーカ | Vishay Siliconix | ||
ロゴ | |||
このページの下部にプレビューとGS7660ISダウンロード(pdfファイル)リンクがあります。 Total 9 pages
GS7660
New Product
Vishay
formerly General Semiconductor
Switched-Capacitor Voltage Converter
8 Pin Dip
SO-8
Features
• Low output impedance ( typical 35Ω at VIN = 5V )
• Low quiescent current ( typical 36µA at VIN = 5V)
• High power conversion efficiency ( typical 98% )
• Simple and accurate voltage conversion from
positive to negative polarities
• Improved latch-up protection
• No external diodes required
Applications
• – 5V supply from + 5V logic supply
• EIA/TIA – 232E and EIA/TIA – 562 power supplies
• Portable telephones
• Data acquisition systems
• Personal communications equipment
• Panel meters
• Handheld instruments
Description
The GS7660 is a monolithic CMOS switched capacitor
voltage converter, designed to be an improved direct
replacement of the popular ICL7660, MAX1044 and
LTC1044. They perform supply voltage conversions from
positive to negative for an input voltage range of +1.5V to
+6.0V to their negative complements of –1.5V to –6.0V.
The input voltage can also be doubled (VOUT = 2VIN),
halved (VOUT = VIN/2), or multiplied (VOUT = ± n.VIN).
Contained on the chip are a series Power Supply regula-
tor, Oscillator, control Circuitry and four Power MOS
Switches. The oscillator, when unloaded, oscillates at a
nominal frequency of 10 kHz, with an Input voltage of 5.0V.
This frequency can be lowered by the addition of an external
capacitor to the “Osc” terminal or overdriven by an external
frequency source.
An Oscillator “boost” function is available to increase the
oscillator frequency which will optimize performance of
certain parameters. The Lv input can be connected to
ground to improve low voltage operation (VIN ≤ 3V), or left
open for input voltages greater than 3V to reduce power
dissipation.
The GS7660 provides superior performance over earlier
designs by combining low output impedance and low qui-
escent current with high efficiency and by eliminating diode
voltage drop losses. The only external components
required are two low cost electrolytic capacitors.
Typical Application Circuit
VIN (1.5V to 6V)
10µF +
C1
15
26
GS7660
37
Required for
VIN 3V
4 8 VOUT = --VIN
10µF
+ C2
Negative Voltage Converter
Document Number 74819
24-May-02
www.vishay.com
1
1 Page GS7660
Vishay
formerly General Semiconductor
Maximum Ratings Ratings at 25°C ambient temperature unless otherwise specified.
Parameter
Symbol
Value
Unit
Supply Voltage (VIN to GND)
Input Voltage (Pin 1, 6 and 7)
VIN 6.0
VIN –0.3V ≤ VIN ≤ (VIN, +0.3V)
V
V
LV Input Current
LV1 20 µA
Output Short Circuit Duration
Continuous
Operating Junction Temperature Range
TJ –40 to +125 °C
Storage Temperature Range
TS –65 to +150 °C
Continuous Power Dissipation
Plastic Dip (Derate 7.9mW/°C above 70°C)
SO-8 (Derate 6mW/°C above 70°C)
PD 630 mW
480
Note: (1) Stresses beyond those listed above may cause permanent damage to the device. Operating at the levels stated above may affect device reliabllity.
Electrical Characteristics VIN = 5.0V LVPin = open, Oscillator free running, I load = 0mA, TA = –40°C to +125°C unless otherwise noted.
Parameter
Conditions
Min Typ Max Unit
Supply Current
LV = Open
TA = 25°C
–
–
36 70
– 100 µA
Pin 1,7, VIN = 3V
– 20 –
Supply Voltage(1)
RL = 10KΩ, LV Open
RL = 10KΩ, LV Gnd
3.0
1.5
–
–
6.0
6.0
V
Output Resistance
IL = 20mA, FOSC = 10kHz TA = 25°C
LV = Open
IL = 3mA, FOSC = 1kHz TA = 25°C
VIN = 2V, LV to Gnd
–
–
–
–
35 70
– 110
– 250
– 370
Ω
Oscillator Frequency
COSC = 0pF, LV to Gnd
Pin 1 Open
VIN = 5.0V
VIN = 2.0V
–
2.0
5.0
–
– kHz
–
Power Efficiency
RL = 5K, FOSC =10kHz, LV = Open
96
98
–
%
Voltage Conversion Efficiency
LV = Open
TA = 25°C
98
99.9
–
%
Oscillator Sink or
Source Current
VOSC = 0V or VIN
LV = Open
Pin 1 = 0V
Pin 1 = VIN
–
–
– 3.0 µA
– 20
Oscillator Impedance
VIN = 2.0V
–
1.0
–
mΩ
TA = 25°C
VIN = 5.0V
–
100
–
kΩ
Note: (1) The GS7660 can operate with or without an external output diode over the full temperature and voltage range. Eliminating the diode reduces voltage
drop losses.
Document Number 74819
24-May-02
www.vishay.com
3
3Pages GS7660
Vishay
formerly General Semiconductor
f
VIN
VOUT
C1 C2 RLOAD
Fig. 8 – Switched Capacitor Model
To better understand the theory of operation, a review of
the basic switched capacitor building block is helpful (see
Fig. 8). Referring to Fig. 8 and looking at one full cycle of
operation, the charge being drained by the load is Qavg or
IL x T (T being the time period of one full cycle).
All the charge (∆q) flowing into the output is being delivered
by the input to C1 during only half the cycle. Under steady-
state condition, C1 will charge to the level of the input voltage
(VIN) and discharge to the peak level of the output voltage
(VOUT). Therefor the voltage change on C1 is VIN – VOUT.
Qavg = ∆q = C1(Vin –Vout)
IL x T = C1(Vin –Vout) or IL = f x C1(Vin –Vout) f = 1/T
IL
=
(Vin
–Vout)
1
and
REQUIV =
1
f x C1
(See fig. 9)
f x C1
Where f is one-half the oscillator frequency. This resistance
is a major component of the output resistance of switched
capacitor circuits.
With C1 = C2 = 10µF and Fosc = 10kHz, this resistance
represents 20Ω.
Under the same conditions, the typical value in the
“Electrical Characteristics” section of the GS7660 is 35Ω.
Design Information
Low Voltage (LV) Pin
Fig. 10 (below) shows a simplified circuit diagram of the
GS7660.
It shows a voltage regulator between the VIN and Gnd, in
series with the Oscillator.
Grounding the LV pin removes the regulator from this
series path and improves low voltage performance down to
1.5V. For supply voltages less than 3.0V, the LV pin should
be connected to ground and left open for voltages above
3.0V.
The LV pin can be left grounded over the total range of
Input Voltages. This will improve low voltage operation and
increase oscillator frequency. The disadvantage is
increased quiescent current and reduced efficiency at
higher voltages.
1M
BOOST
pin 1
OSC
pin 7
Q
÷2 Q
LV
pin 6
VIN
pin 8
S1
CAP+
pin 2
S2
S3 S4
GND CAP-
pin 3 pin 4
VOUT
pin 5
Fig. 10 – Functional Diagram
REQUIV
VIN
REQUIV =
1
f × C1
C2
VOUT
RLOAD
Fig. 9 – Equivalent Impedance
www.vishay.com
6
Document Number 74819
24-May-02
6 Page | |||
ページ | 合計 : 9 ページ | ||
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部品番号 | 部品説明 | メーカ |
GS7660IP | Switched-Capacitor Voltage Converter | Vishay Siliconix |
GS7660IS | Switched-Capacitor Voltage Converter | Vishay Siliconix |