MC34166 Datasheet, PDF (1/20 Pages) ON Semiconductor – POWER SWITCHING REGULATORS

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 µA.
• 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 µA
• Economical 5–Lead TO–220 Package with Two Optional Leadforms
• Also Available in Surface Mount D²PAK Package
• Moisture Sensitivity Level (MSL) Equals 1
V_in
I_LIMIT
4
Oscillator
S
Q
R
2
PWM
UVLO
Thermal
L
Reference
EA
1
V_O
5.05 V/
3.0 A
3
5
This device contains 143 active transistors.
Figure 1. Simplified Block Diagram
(Step Down Application)
http://onsemi.com
x = 3 or 4
A = Assembly Location
WL = Wafer Lot
Y = Year
WW = Work Week
MARKING
DIAGRAMS
1
5
TO–220
TH SUFFIX
CASE 314A
MC
3x166T
AWLYWW
1
5
TO–220
TV SUFFIX
CASE 314B
MC
3x166T
AWLYWW
Heatsink surface connected to Pin 3
TO–220
MC
T SUFFIX
3x166T
CASE 314D
AWLYWW
1
5
Pin 1. Voltage Feedback Input
2. Switch Output
3. Ground
4. Input Voltage/V_CC
5. Compensation/Standby
1
5
D²PAK
D2T SUFFIX
CASE 936A
MC
3x166T
AWLYWW
Heatsink surface (shown as
terminal 6 in case outline
drawing) is connected to Pin 3 ¹
5
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 17 of this data sheet.
© Semiconductor Components Industries, LLC, 2002
1
January, 2002 – Rev. 6
Publication Order Number:
MC34166/D