CS2844 Datasheet, PDF (1/12 Pages) Cherry Semiconductor Corporation – Current Mode PWM Control Circuit with 50% Max Duty Cycle

CS2844, CS3844, CS2845,
CS3845
Current Mode PWM
Control Circuit with
50% Max Duty Cycle
The CS3844/45 provides all the necessary features to implement
off–line fixed frequency current–mode control with a minimum
number of external components.
The CS3844 family incorporates a new precision
temperature–controlled oscillator to minimize variations in frequency.
An internal toggle flip–flop, which blanks the output every other clock
cycle, limits the duty–cycle range to less than 50%. An undervoltage
lockout ensures that V_REF is stabilized before the output stage is
enabled. In the CS2844/CS3844 turn on occurs at 16 V and turn off at
10 V. In the CS2845/CS3845 turn on is at 8.4 V and turn off at 7.6 V.
Other features include low start–up current, pulse–by–pulse current
limiting, and a high–current totem pole output for driving capacitive
loads, such as gate of a power MOSFET. The output is low in the off
state, consistent with N–channel devices.
Features
• Optimized for Off–Line Control
• Temp. Compensated Oscillator
• 50% Max Duty–Cycle Clamp
• V_REF Stabilized Before Output Stage Is Enabled
• Low Start–Up Current
• Pulse–By–Pulse Current Limiting
• Improved Undervoltage Lockout
• Double Pulse Suppression
• 1.0% Trimmed Bandgap Reference
• High Current Totem Pole Output
http://onsemi.com
MARKING
DIAGRAMS
8
8
1
8
1
14
1
16
1
DIP–8
N SUFFIX
CASE 626
SO–8
D SUFFIX
CASE 751
CSx84yN
AWL
YYWW
1
8
384yD
ALYW
SO–14
D SUFFIX
CASE 751A
1
14
CSx84yD14
AWLYWW
1
16
SO–16L
DW SUFFIX
CASE 751G
CSx84yDW
AWLYYWW
1
x
= 2 or 3
y
= 4 or 5
A
= Assembly Location
WL, L = Wafer Lot
YY, Y = Year
WW, W = Work Week
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 7 of this data sheet.
© Semiconductor Components Industries, LLC, 2001
1
June, 2001 – Rev. 3
Publication Order Number:
CS2844/D