|
|
Número de pieza | AN023 | |
Descripción | An Useful Model for Charge Pump Converter | |
Fabricantes | AIC | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de AN023 (archivo pdf) en la parte inferior de esta página. Total 6 Páginas | ||
No Preview Available ! AN023
An Useful Model for Charge Pump Converter
Introduction
Analysis
This application note focuses on the analysis of
the charge pump and its equivalent circuit. The
AIC1845 is a micro-power charge pump DC/DC
converter that produces a regulated 5V output. This
kind of converter uses capacitors to store and transfer
energy. Since the capacitors can not change their
voltage level abruptly, the voltage ratio of VOUT over VIN
is limited to some range. Capacitive voltage conversion
is obtained by switching a capacitor periodically. It first
charges the capacitor by connecting it across a voltage
source and then connects it to the output. Referring to
Fig.1, During the on state of internal clock, Q1 and Q4
are closed, which charges C1 to VIN level. During the off
state, Q3 and Q2 are closed. The output voltage is VIN
plus VC1, that is, 2 VIN.
VIN
CIN
ION Q1
Q2
RDS-ON ESR
VOU T
COUT
Q3 C1 Q4
RDS-ON
Fig.2 The on State of Charge Pump Circuit
VIN
CIN
RDS-ON
Q1 Q2 VOU T
ESR COUT
Q3
RDS-ON
IOFF
C1 Q4
Fig.3 The OFF State of Charge Pump Circuit
VIN
Q1
CIN
Q2 VOUT
C1 COUT
Q3 Q4
Fig.1 The Circuit of Charge Pump
Referring to Fig.2 and Fig.3, here shows the circuit of
charge pump at different states of operation. RDS-ON is
the resistance of the switching element at conduction.
ESR is the equivalent series resistance of the flying
capacitor C1. ION-AVE and IOFF-AVE are the average
current during on state and off state, respectively. D is
the duty cycle, which means the proportion the on state
takes. Let’s take advantage of conversation of charge
for capacitor C1. Assume that the capacitor C1 has
reached its steady state. The amount of charge flowing
into C1 during on state is equal to that flowing out of C1
at off state.
ION−AVE × DT = IOFF−AVE × (1− D)T
ION-AVE × D = IOFF-AVE × (1− D)
(1)
(2)
February, 2002
1
1 page AN023
Fig.6 The Simulation Circuit of AIC1845
Table. 1 The experiment results and the evaluated RDS-ON.
VIN (V) RLOAD (Ω) ESR (mΩ) VOUT (V) IOUT (mA)
Frequency(KHz)
RDS-ON(Ω)
2.7 99.4
2.7 109.4
2.7 121.2
2.7 131.3
2.7 141.2
20
20
20
20
20
4.77
4.83
4.89
4.92
4.95
48.20
44.30
40.32
37.49
35.07
640
640
640
640
640
1.43
1.40
1.38
1.40
1.40
Table. 2 The simulation results. (RDS-ON is from Table.1)
VIN(V)
RLOAD(Ω)
ESR(mΩ) RDS-ON(Ω)
Frequency
(kHz)
2.7 99.4 20 1.43 640
2.7 109.4
20
1.40
640
2.7 121.2
20
1.38
640
2.7 131.3
20
1.40
640
2.7 141.2
20
1.40
640
VOUT(V)
4.83
4.89
4.94
4.97
5.00
IOUT(V)
48.62
44.68
40.77
37.84
35.38
5
5 Page |
Páginas | Total 6 Páginas | |
PDF Descargar | [ Datasheet AN023.PDF ] |
Número de pieza | Descripción | Fabricantes |
AN020 | The Power Management of PDA | AIC |
AN021 | A Handy Method to Obtain Satisfactory Response of Buck Converter | AIC |
AN022 | High Side Driver | AIC |
AN023 | An Useful Model for Charge Pump Converter | AIC |
Número de pieza | Descripción | Fabricantes |
SLA6805M | High Voltage 3 phase Motor Driver IC. |
Sanken |
SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |