SPW3842D Datasheet, PDF (1/10 Pages) SeCoS Halbleitertechnologie GmbH – High Performance Current Mode Controlers

Elektronische Bauelemente
SPW3842D
High Performance Current Mode
Controlers
RoHS Compliant Product
Description
The SPW3842D is high performance fixed frequency current mode
controllers. This is specifically designed for Off-Line and DC TO DC
converter applications offering the designer a cost-effective solution
with min. external components. These integrated circuits feature a
trimmed oscillator for precise duty cycle control. A temperature
compensated reference, high gain Error amplifier, 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 undervoltages lockouts each with
hysteresis, cycle-by-cycle current limiting, proprammable output
deadtime, and latch for single pulse metering.
SEATING PLANE
Features
DIP-8
D
ZZ
be
GAUGE PLANE
b
SECTION Z - Z
* Low Startup And Operating Current
* Automatic Feed Forward Compensation
* High Current Totem Pole Output
* Trimmed Oscillator For Precise Frequency Control
* Oscillator Frequency Graranteed At 250kHz
* Undervoltage Lockout With Hysteresis
* Current Mode Operation To 500kHz
* Internally Trimmed Reference With Undervoltage Lockout
* Iatching PWM For Cycle-By-Cycle Current Limiting
REF.
A
A1
A2
b
b1
b2
b3
c
Millimeter
Min.
Max.
-
0.5334
0.381
-
2.921
4.953
0.356
0.559
0.356
0.508
1.143
1.778
0.762
1.143
0.203
0.356
REF.
c1
D
E
E1
e
HE
L
Millimeter
Min. Max.
0.203
0.279
9.017
10.16
6.096
7.112
7.620
8.255
2.540 BSC
-
10.92
2.921
3.810
DIP-8L
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
rogrammed by
pacitor CT to ground .Operation 500kHz
Function
Pin1:Compensation
Pin2:Voltage Feedback
Pin3:Current Sense
Pin4:RT/CT
Pin5:Ground
Pin6:Output
Pin7:Vcc
Pin8:Vref
Description
nts up to
This pin is the Error Amplifier output and is made available for loop
coTmhipseinssathtieonr.eference _{output .It provides charging current for capacitor CT}
This is the inverting input of the Error Amplifier. It’s normally connected to the
Switching power supply output through a resistor divider.
A voltage proportional to inductor current is connected to this input .The
PWM uses this information to terminate the output switch conduction.
The oscillator frequency and maximum output duty cycle are programmed by
connecting resistor RT to Vref and capacitor CT to ground. Operation 500kHz
is possible.
This pin is the combined control circuitry and power ground.
This output directly drives the gate of a power MOSFET. Peak currents up to
1 A are sourced and sunk by this pin.
This pin is the positive supply of the control IC.
This is the reference output. It provides charging current for capacitor CT
through resistor RT.
Any changing of specification will not be informed individual
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