MC34166, MC33166
3.0 A, Step−Up/Down/
Inverting Switching
Regulators
The MC34166, MC33166 series are high performance fixed
frequency power switching regulators that contain the primary
functions required for dc−to−dc converters. This series was specifically
designed to be incorporated in step−down and voltage−inverting
configurations with a minimum number of external components and
can also be used cost effectively in step−up applications.
These devices consist of an internal temperature compensated
reference, fixed frequency oscillator with on−chip timing components,
latching pulse width modulator for single pulse metering, high gain
error amplifier, and a high current output switch.
Protective features consist of cycle−by−cycle current limiting,
undervoltage lockout, and thermal shutdown. Also included is a low
power standby mode that reduces power supply current to 36 mA.
http://onsemi.com
x
A
WL
Y
WW
G
= 3 or 4
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
TO−220
TH SUFFIX
CASE 314A
Output Switch Current in Excess of 3.0 A
Fixed Frequency Oscillator (72 kHz) with On−Chip Timing
Provides 5.05 V Output without External Resistor Divider
Precision 2% Reference
0% to 95% Output Duty Cycle
Cycle−by−Cycle Current Limiting
Undervoltage Lockout with Hysteresis
Internal Thermal Shutdown
Operation from 7.5 V to 40 V
Standby Mode Reduces Power Supply Current to 36 mA
Economical 5−Lead TO−220 Package with Two Optional Leadforms
Also Available in Surface Mount D2PAK Package
Moisture Sensitivity Level (MSL) Equals 1
Pb−Free Packages are Available
MC
3x166T
AWLYWWG
TO−220
TV SUFFIX
CASE 314B
Features
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MARKING
DIAGRAMS
MC
3x166T
AWLYWWG
1
5
1
5
Heatsink surface connected to Pin 3
Vin
4
ILIMIT
Oscillator
TO−220
T SUFFIX
CASE 314D
1
S
Q
2
R
5
Pin
PWM
UVLO
Thermal
L
1.
2.
3.
4.
5.
Reference
EA
1
VO
5.05 V/
3.0 A
3
5
This device contains 143 active transistors.
October, 2005 − Rev. 7
Voltage Feedback Input
Switch Output
Ground
Input Voltage/VCC
Compensation/Standby
D2PAK
D2T SUFFIX
CASE 936A
1
MC
3x166T
AWLYWWG
5
Heatsink surface (shown as
terminal 6 in case outline
drawing) is connected to Pin 3
1
5
ORDERING INFORMATION
Figure 1. Simplified Block Diagram
(Step Down Application)
© Semiconductor Components Industries, LLC, 2005
MC
3x166T
AWLYWWG
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
1
Publication Order Number:
MC34166/D
