|
|
PDF CM3706 Data sheet ( Hoja de datos )
| Número de pieza | CM3706 | |
| Descripción | Synchronous Step-Down Regulator | |
| Fabricantes | Champion | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de CM3706 (archivo pdf) en la parte inferior de esta página. Total 11 Páginas | ||
|
No Preview Available !
CM3706
1.5MHz, 600mA Synchronous
Step-Down Regulator
GENERAL DESCRIPTION
FEATURES
The CM3706 is a 1.5MHz constant frequency, slope
compensated current mode PWM step-down converter.
The device integrates a main switch and a synchronous
rectifier for high efficiency without an external Schottky
diode. It is ideal for powering portable equipment that runs
from a single cell lithium-Ion (Li+) battery. The CM3706
can supply 600mA of load current from a 2.5V to 5.5V
input voltage. The output voltage can be regulated as
low as 0.6V. The CM3706 can also run at 100% duty cycle
for low dropout operation, extending battery life in portable
system. Idle mode operation at light loads provides very
low output ripple voltage for noise sensitive applications.
The CM3706 is offered in a low profile (1mm) 5-pin, thin
TSOT package, and is available in an adjustable version.
◆ High Efficiency: Up to 96%
◆ 1.5Mhz Constant Switching Frequency
◆ 600mA Output Current at VIN=3V
◆ Integrated Main switch and synchronous rectifier. No
Schottky Diode Required
◆ 2.5V to 5.5V Input Voltage Range
◆ Output Voltage as Low as 0.6V
◆ 100% Duty Cycle in Dropout
◆ Low Quiescent Current: 300µA
◆ Slope Compensated Current Mode Control for Excellent Line
and Load Transient Response
◆ Short Circuit Protection
◆ Thermal Fault Protection
◆ <1uA Shutdown Current
◆ Space Saving 5-Pin Thin TSOT23 package
APPLICATIONS
Cellular and Smart Phones
Microprocessors and DSP Core Supplies
Wireless and DSL Modems
PDAs
MP3 Players
www.DataSheet4U.com
Portable Instruments
Digital Still and Video Cameras
TYPICAL APPLICATIONS
IN
2.5V TO
5.5V
Cin
4.7uF
4
VIN
SW
CM3706
1 RUN GND V FB
2
3
5
316K
2.2uH
634k
22PF
OUT
Cout
10uF
Figure 1. Basic Application Circuit with CM3706 adjustable version
2006/12/20Rev. 1.6
Champion Microelectronic Corporation
Page 1
1 page  
CM3706
1.5MHz, 600mA Synchronous
Step-Down Regulator
FUNCTIONAL DESCRIPTION
Operation
CM3706 is a monolithic switching mode Step-Down DC-DC
converter. It utilizes internal MOSFETs to achieve high
efficiency and can generate very low output voltage by using
internal reference at 0.6V. It operates at a fixed switching
frequency, and uses the slope compensated current mode
architecture. This Step-Down DC-DC Converter supplies
600mA output current at VIN = 3V with input voltage range
from 2.5V to 5.5V.
Idle Mode Operation
At very light loads, the CM3706 automatically enters Idle
Mode. In the Idle Mode, the inductor current may reach zero
or reverse on each pulse. The PWM control loop will
automatically skip pulses to
maintain output regulation. The bottom MOSFET is turned
off by the current reversal comparator, IZERO, and the switch
voltage will ring. This is discontinuous mode operation, and
is normal behavior for the switching regulator.
Current Mode PWM Control
Slope compensated current mode PWM control provides
stable switching and cycle-by-cycle current limit for excellent
load and line responses and protection of the internal main
switch (P-Ch MOSFET) and synchronous rectifier (N-CH
MOSFET). During normal operation, the internal P-Ch
MOSFET is turned on for a certain time to ramp the inductor
current at each rising edge of the internal oscillator, and
switched off when the peak inductor current
is above the error voltage. The current comparator, ICOMP,
limits
the peak inductor current. When the main switch is off, the
synchronous rectifier will be turned on immediately and stay
on until either the inductor current starts to reverse, as
indicated by the current reversal comparator, IZERO, or the
beginning of the next clock cycle. The OVDET comparator
controls output transient overshoots by turning the main
switch off and keeping it off until the fault is no longer present.
Maximum Load Current
The CM3706 will operate with input supply voltage as
low as 2.5V, however, the maximum load current
decreases at lower input due to large IR drop on the
main switch and synchronous rectifier. The slope
compensation signal reduces the peak inductor current
as a function of the duty cycle to prevent sub-harmonic
oscillations at duty cycles greater than 50%.
Conversely the current limit increases as the duty cycle
decreases.
Note 5: The duty cycle D of a step-down converter is defined
as:
D
= TON
×
f OSC
×100%
≈ V OUT
VIN
×100%
where TON is the main switch on time, and fOSC is the oscillator
frequency (1.5Mhz).
Dropout Operation
When the input voltage decreases toward the value of the
output voltage, the CM3706 allows the main switch to remain
on for more than one switching cycle and increases the duty
cycle (Note 5) until it reaches 100%. The output voltage then
is the input voltage
minus the voltage drop across the main switch and the
inductor. At low input supply voltage, the RDS(ON) of the
P-Channel MOSFET increases, and the efficiency of the
converter decreases. Caution must be exercised to ensure
the heat dissipated not to exceed the maximum junction
temperature of the IC.
2006/12/20Rev. 1.6
Champion Microelectronic Corporation
Page 5
5 Page 
CM3706
1.5MHz, 600mA Synchronous
Step-Down Regulator
IMPORTNT NOTICE
Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue
any integrated circuit product or service without notice, and advises its customers to obtain the latest version of
relevant information to verify, before placing orders, that the information being relied on is current.
A few applications using integrated circuit products may involve potential risks of death, personal injury, or severe
property or environmental damage. CMC integrated circuit products are not designed, intended, authorized, or
warranted to be suitable for use in life-support applications, devices or systems or other critical applications. Use of
CMC products in such applications is understood to be fully at the risk of the customer. In order to minimize risks
associated with the customer’s applications, the customer should provide adequate design and operating
safeguards.
HsinChu Headquarter
5F, No. 11, Park Avenue II,
Science-Based Industrial Park,
HsinChu City, Taiwan 300
T E L : +886-3-567 9979
F A X : +886-3-567 9909
http://www.champion-micro.com
Sales & Marketing
7F-6, No.32, Sec. 1, Chenggong Rd.,
Nangang District, Taipei City 115, Taiwan
T E L : +886-2-2788 0558
F A X : +886-2-2788 2985
2006/12/20Rev. 1.6
Champion Microelectronic Corporation
Page 11
11 Page | ||
| Páginas | Total 11 Páginas | |
| PDF Descargar | [ Datasheet CM3706.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| CM3702 | Micropower Low-Noise Charge-Pump and Linear Regulator |  California Micro Devices |
| CM3706 | Synchronous Step-Down Regulator | Champion |
| CM3708 | 3A LOOW NOISE PWM STEP DOWN REGULATOR |  ETC |
| CM3708A | 3A LOW LOISE PWM STEP DOWN REGULATOR | ETC |
| 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 |