Zakładka z wyszukiwarką danych komponentów
  Polish  ▼
ALLDATASHEET.PL

X  

TC7662A Arkusz danych(PDF) 8 Page - Microchip Technology

Numer części TC7662A
Szczegółowy opis  Charge Pump DC-to-DC Converter
Download  16 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Producent  MICROCHIP [Microchip Technology]
Strona internetowa  http://www.microchip.com
Logo MICROCHIP - Microchip Technology

TC7662A Arkusz danych(HTML) 8 Page - Microchip Technology

Back Button TC7662A_13 Datasheet HTML 4Page - Microchip Technology TC7662A_13 Datasheet HTML 5Page - Microchip Technology TC7662A_13 Datasheet HTML 6Page - Microchip Technology TC7662A_13 Datasheet HTML 7Page - Microchip Technology TC7662A_13 Datasheet HTML 8Page - Microchip Technology TC7662A_13 Datasheet HTML 9Page - Microchip Technology TC7662A_13 Datasheet HTML 10Page - Microchip Technology TC7662A_13 Datasheet HTML 11Page - Microchip Technology TC7662A_13 Datasheet HTML 12Page - Microchip Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 16 page
background image
TC7662A
DS21468B-page 8
 2001-2012 Microchip Technology Inc.
4.5
Changing the TC7662A Oscillator
Frequency
It is possible to increase the conversion efficiency of
the TC7662A at low load levels by lowering the
oscillator frequency. This reduces the switching losses,
and is shown in Figure 4-5. However, lowering the
oscillator frequency will cause an undesirable increase
in the impedance of the pump (CP) and reservoir (CR)
capacitors; this is overcome by increasing the values of
CP and CR by the same factor that the frequency has
been reduced. For example, the addition of a 100pF
capacitor between pin 7 (OSC) and VDD will lower the
oscillator frequency to 2kHz from its nominal frequency
of 12kHz (multiple of 6), and thereby necessitate a
corresponding increase in the value of CP and CR (from
10
F to 68F).
FIGURE 4-5:
LOWERING OSCILLATOR
FREQUENCY
4.6
Positive Voltage Doubling
The TC7662A may be employed to achieve positive
voltage doubling using the circuit shown in Figure 4-6.
In this application, the pump inverter switches of the
TC7662A are used to charge CP to a voltage level of
VDD – VF (where VDD is the supply voltage and VF is
the forward voltage on CP plus the supply voltage (VDD)
applied through diode D2 to capacitor CR). The voltage
thus created on CR becomes (2 VDD) – (2 VF), or twice
the supply voltage minus the combined forward voltage
drops of diodes D1 and D2.
The source impedance of the output (VOUT) will depend
on the output current, but for VDD = 5V and an output
current of 10 mA, it will be approximately 60
.
FIGURE 4-6:
POSITIVE VOLTAGE
MULTIPLIER
4.7
Combined Negative Voltage
Conversion and Positive Supply
Multiplication
Figure 4-7 combines the functions shown in Figure 4-1
and Figure 4-6 to provide negative voltage conversion
and positive voltage doubling simultaneously. This
approach would be, for example, suitable for generat-
ing +9V and -5V from an existing +5V supply. In this
instance, capacitors C1 and C3 perform the pump and
reservoir functions, respectively, for the generation of
the negative voltage, while capacitors C2 and C4 are
pump and reservoir, respectively, for the doubled
positive voltage. There is a penalty in this configuration
which combines both functions, however, in that the
source impedances of the generated supplies will be
somewhat higher due to the finite impedance of the
common charge pump driver at pin 2 of the device.
FIGURE 4-7:
COMBINED NEGATIVE
CONVERTER AND
POSITIVE DOUBLER
4.8
Voltage Splitting
The same bidirectional characteristics can be used to
split a higher supply in half, as shown in Figure 4-8.
The combined load will be evenly shared between the
two sides. Because the switches share the load in
parallel, the output impedance is much lower than in
the standard circuits, and higher currents can be drawn
from the device. By using this circuit, and then the
circuit of Figure 4-4, +15V can be converted (via +7.5V
and -7.5V) to a nominal -15V, though with rather high
series resistance (~250
).
FIGURE 4-8:
SPLITTING A SUPPLY IN
HALF
1
2
3
4
8
7
6
5
+
VOUT
COSC
+
TC7662A
10
μF
10
μF
VDD
1
2
3
4
8
7
6
5
VOUT =
(2 VDD) – (2 VF)
+
CR
D1
D2
+
CP
TC7662A
VDD
1
2
3
4
8
7
6
5
+
VDD
VOUT =
(2 VDD) – (2 VF)
C1
D1
+
+
C3
C4
VOUT =
-(VDD – VF)
C2
TC7662A
D2
+
+
RL1
RL2
VOUT =
VDD – V
2
50
μF
50
μF
VDD
V –
50
μF
+
1
2
8
7
TC7662A
3
4
6
5
+


Podobny numer części - TC7662A_13

ProducentNumer częściArkusz danychSzczegółowy opis
logo
TelCom Semiconductor, I...
TC7662ACPA TELCOM-TC7662ACPA Datasheet
62Kb / 5P
   CHARGE PUMP DC-TO-DC CONVERTER
logo
Microchip Technology
TC7662ACPA MICROCHIP-TC7662ACPA Datasheet
53Kb / 7P
   CHARGE PUMP DC-TO-DC CONVERTER
2001
TC7662ACPA MICROCHIP-TC7662ACPA Datasheet
457Kb / 14P
   Charge Pump DC-to-DC Converter
2002
logo
TelCom Semiconductor, I...
TC7662AEPA TELCOM-TC7662AEPA Datasheet
62Kb / 5P
   CHARGE PUMP DC-TO-DC CONVERTER
logo
Microchip Technology
TC7662AEPA MICROCHIP-TC7662AEPA Datasheet
53Kb / 7P
   CHARGE PUMP DC-TO-DC CONVERTER
2001
More results

Podobny opis - TC7662A_13

ProducentNumer częściArkusz danychSzczegółowy opis
logo
TelCom Semiconductor, I...
TC7662A TELCOM-TC7662A Datasheet
62Kb / 5P
   CHARGE PUMP DC-TO-DC CONVERTER
logo
Microchip Technology
TC7662A MICROCHIP-TC7662A Datasheet
53Kb / 7P
   CHARGE PUMP DC-TO-DC CONVERTER
2001
TC7662A MICROCHIP-TC7662A_02 Datasheet
457Kb / 14P
   Charge Pump DC-to-DC Converter
2002
TC7660 MICROCHIP-TC7660 Datasheet
91Kb / 12P
   CHARGE PUMP DC-TO-DC VOLTAGE CONVERTER
2001
logo
ON Semiconductor
MC7660 ONSEMI-MC7660 Datasheet
191Kb / 12P
   Charge Pump DC-to-DC Voltage Converter
February, 2000 ??Rev. 2
logo
Microchip Technology
TC1044S MICROCHIP-TC1044S Datasheet
92Kb / 11P
   Charge Pump DC-TO-DC Voltage Converter
2001
logo
TelCom Semiconductor, I...
TC1044S TELCOM-TC1044S Datasheet
141Kb / 8P
   CHARGE PUMP DC-TO-DC VOLTAGE CONVERTER
TC7662B TELCOM-TC7662B Datasheet
133Kb / 9P
   CHARGE PUMP DC-TO-DC VOLTAGE CONVERTER
logo
Microchip Technology
TC7660 MICROCHIP-TC7660_16 Datasheet
1Mb / 20P
   Charge Pump DC-to-DC Voltage Converter
11/29/11
TC7660 MICROCHIP-TC7660_02 Datasheet
386Kb / 18P
   Charge Pump DC-to-DC Voltage Converter
2002
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


Arkusz danych Pobierz

Go To PDF Page


Link URL




Polityka prywatności
ALLDATASHEET.PL
Czy Alldatasheet okazała się pomocna?  [ DONATE ] 

O Alldatasheet   |   Reklama   |   Kontakt   |   Polityka prywatności   |   Linki   |   Lista producentów
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com