ZXRD1000 Datasheet, PDF (1/28 Pages) Zetex Semiconductors – HIGH EFFICIENCY SIMPLESYNC PWM DC-DC CONTROLLERS

ZXRD1000 SERIES
HIGH EFFICIENCY SIMPLESYNC PWM DC-DC CONTROLLERS
DESCRIPTION
The ZXRD1000 series provides complete control and
protection functions for a high efficiency (> 95%) DC-DC
converter solution. The choice of external MOSFETs allow
the designer to size devices according to application. The
ZXRD1000 series uses advanced DC-DC converter
techniques to provide synchronous drive capability, using
innovative circuits that allow easy and cost effective
implementation of shoot through protection. The
FEATURES
• > 95% Efficiency
• Fixed frequency (adjustable) PWM
• Voltage mode to ensure excellent stability &
transient response
• Low quiescent current in shutdown mode,15µA
• Low battery flag
• Output down to 2.0V
• Overload protection
• Demonstration boards available
• Synchronous or non-synchronous operation
• Cost effective solution
• N or P channel MOSFETs
• QSOP16 package
ZXRD1000 series can be used with an all N channel
topology or a combination N & P channel topology.
Additional functionality includes shutdown control, a
user adjustable low battery flag and simple
adjustment of the fixed PWM switching frequency.
The controller is available with fixed outputs of 5V or
3.3V and an adjustable (2.0 to 12V) output.
• Fixed 3.3, 5V and adjustable outputs
• Programmable soft start
APPLICATIONS
• High efficiency 5 to 3.3V converters up to 4A
• Sub-notebook computers
• Embedded processor power supply
• Distributed power supply
• Portable instruments
• Local on card conversion
• GPS systems
Very high efficiency SimpleSync^TM converter.
VCC
4.5-10V
Shut Down
Low input flag
CIN
68µF
R1
100k
IC1
9 _SHDN
13
VIN
VDRIVE ²
C10
1µF
C1
1µF
C5
LBSET Bootstrap ¹
1µF
11 _LBF
RSENSE+ ⁷
C2 330pF
1µF C3
14
10
6
5
Delay
Decoup
VINT
CT
GND
4
1µF
C4
RSENSE - ⁸
VFB ¹⁶
Comp
PWR
15
GND
3
C7
22µF
C6
1µF
R6820RC0X.0122µF
RX
2k7
R4
10k
D2
BAT54
ZXM64N02X
N1
C11
1µF
L1
15µH
Fx
D3
BAT54
N2
ZXM64N02X
C8
D1
2.2µF
ZHCS1000
R3
3k
RSENSE
0.01R
VOUT
3.3V 4A
R6 Cx2
10k
0.01µF
COUT
C9
1µF
x2
680µF 120µF
R5
6k
ISSUE 4 - OCTOBER 2000
1