MC34063A
DC-to-DC Converter Control Circuits
DESCRIPTION
The MC34063A Series is a monolithic control
circuit containing the primary functions required for
DC-to-DC converters. These devices consist of an
converters. Temperature compensated reference,
Comparator,controlled duty cycle oscillator with an
active current limit circuit,driver and high current
output switch. This series was specifically designed to
be incorporated in Step-Down and Step-Up and
Voltage applications with a minimum number of
external components.
The MC34063 is available in the plastic DIP-8,
SOP-8 and SOIC-8 package.
Features
Operation from 3.0V to 40 V Input
Low Standby Current
Current limiting
Output Switch current to 1.5A
Output Voltage Adjustable
Frequency Operature to 100kHz
Precision 2% Reference
APPLICATION
Battery Chargers
NICs/Switches/Hubs
ADSL Modems
Negative Voltage Power Supplies
ABSOLUTE MAXIMUM RATINGS
ShenZhen CYT IC Design CO . ,Ltd
1
Revision 12/4/2007
All contents are subject to change without prior notice.
MC34063A
ELECTRICAL CHARACTERISTICS
(VCC=5.0 V, Ta=Tlow to Thigh,unless otherwise specified.)
NOTES:
1. Maximum package power dissipation limits must be observed.
2. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to
ambient temperature as possible.
ShenZhen CYT IC Design CO . ,Ltd
2
Revision 12/4/2007
All contents are subject to change without prior notice.
MC34063A
7.
Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient
temperature as possible
.
ShenZhen CYT IC Design CO . ,Ltd
3
Revision 12/4/2007
All contents are subject to change without prior notice.
MC34063A
8. If the output switch is driven into hard saturation (non−Darlington configuration) at low switch currents
(≤ 300 mA) and high driver currents (≥30 mA), it may take up to 2.0
s to come out of saturation. This
condition will shorten the off time at frequencies
≥
30 kHz, and is magnified at high temperatures. This
condition does not occur with a Darlington configuration, since the output switch cannot saturate. If a
non−Darlington configuration is used, the following output drive condition is recommended.
ShenZhen CYT IC Design CO . ,Ltd
4
Revision 12/4/2007
All contents are subject to change without prior notice.
MC34063A
ShenZhen CYT IC Design CO . ,Ltd
5
Revision 12/4/2007
All contents are subject to change without prior notice.