MC34023_05 Datasheet, PDF (1/18 Pages) ON Semiconductor – High Speed Single−Ended PWM Controller

MC34023, MC33023
High Speed Single−Ended
PWM Controller
The MC34023 series are high speed, fixed frequency, single−ended
pulse width modulator controllers optimized for high frequency
operation. They are specifically designed for Off−Line and
DC−to−DC converter applications offering the designer a
cost−effective solution with minimal external components. These
integrated circuits feature an oscillator, a temperature compensated
reference, a wide bandwidth error amplifier, a high speed current
sensing comparator, and a high current totem pole output ideally
suited for driving a power MOSFET.
Also included are protective features consisting of input and
reference undervoltage lockouts each with hysteresis, cycle−by−cycle
current limiting, and a latch for single pulse metering.
The flexibility of this series allows it to be easily configured for
either current mode or voltage mode control.
Features
• 50 ns Propagation Delay to Output
• High Current Totem Pole Output
• Wide Bandwidth Error Amplifier
• Fully−Latched Logic with Double Pulse Suppression
• Latching PWM for Cycle−By−Cycle Current Limiting
• Soft−Start Control with Latched Overcurrent Reset
• Input Undervoltage Lockout with Hysteresis
• Low Startup Current (500 mA Typ)
• Internally Trimmed Reference with Undervoltage Lockout
• 90% Maximum Duty Cycle (Externally Adjustable)
• Precision Trimmed Oscillator
• Voltage or Current Mode Operation to 1.0 MHz
• Functionally Similar to the UC3823
• Pb−Free Packages are Available*
http://onsemi.com
16
1
16
1
PDIP−16
P SUFFIX
CASE 648
SOIC−16W
DW SUFFIX
CASE 751G
MARKING DIAGRAMS
16
16
MC34023P
AWLYYWWG
1
MC33023DW
AWLYYWWG
1
A
= Assembly Location
WL
= Wafer Lot
YY
= Year
WW
= Work Week
G
= Pb−Free Package
PIN CONNECTIONS
16
V_ref
4
Clock
5
R_T
6
C_T
7
Ramp
Error Amp 3
Output
Noninverting
Input
2
Inverting
Input
1
8
Soft−Start
Oscillator
5.1V
Reference
UVLO
Latching
Error
PWM
Amp
Soft−Start
10 Ground
This device contains 176 active transistors.
Figure 1. Simplified Application
15
V_CC
13
V_C
14
Output
12
Power
Ground
11
Current
9
Limit Ref
Current
Limit/
Shutdown
Error Amp
Inverting Input ¹
Error Amp ₂
Noninverting Input
Error Amp Output 3
16 V_ref
15 V_CC
14 Output
Clock ⁴
R_T 5
C_T 6
Ramp 7
Soft−Start ⁸
13 V_C
12 Power Ground
11 ^{Current Limit}
Reference
10 Ground
9 ^{Current Limit/}
Shutdown
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
*For additional information on our Pb−Free strategy
and soldering details, please download the
ON Semiconductor Soldering and Mounting
Techniques Reference Manual, SOLDERRM/D.
© Semiconductor Components Industries, LLC, 2005
1
October, 2005 − Rev. 6
Publication Order Number:
MC34023/D