SECOS SPW3842D

SPW3842D
High Performance Current Mode
Elektronische Bauelemente
Controlers
RoHS Compliant Product
DIP-8
Description
D
GAUGE PLANE
c
A
E
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
b
Z
L
Z
SECTION Z - Z
Features
e
b
* Low Startup And Operating Current
* Automatic Feed Forward Compensation
REF.
* 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
A
A1
A2
b
b1
b2
b3
c
Millimeter
Min.
Max.
0.381
2.921
0.356
0.356
1.143
0.762
0.203
0.5334
4.953
0.559
0.508
1.778
1.143
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
* Iatching PWM For Cycle-By-Cycle Current Limiting
rogrammed by
pacitor CT to ground .Operation 500kHz
DIP-8L
Function
Pin1:Compensation
Pin2:Voltage Feedback
Pin3:Current Sense
Pin4:RT/CT
Pin5:Ground
Pin6:Output
Pin7:Vcc
Pin8:Vref
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Description
nts up to
This pin is the Error Amplifier output and is made available for loop
compensation.
This is the reference 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
Page 1 of 10
SPW3842D
High Performance Current Mode
Elektronische Bauelemente
Controlers
Absolute Maximum Ratings at Ta = 25
Parameter
Symbol
Total power Supply and Zener current
VALUE
Unit
(ICC+Iz)
30
mA
Io
1.0
A
Output current,source or sink(note1)
Output energy(capacitive load per cycle)
W
5.0
Current sense and voltage feedback inputs
Vin
-0.3 to 5.5
Error Amplifier Output Sink Current
J
V
Io
10
mA
Power Dissipation at Thermal
characteristics
PD
P JA
702
178
mW
/W
Storage Temperature Range
Tstg
-65 to 150
Operating Junction Temperature
TJ
+150
Operating ambient Temperature
TA
0~+70
Electrical Characteristics
(0
Parameter
TA 70
,Vcc=15V[note 2],RT=10k,CT =3.3Nf,unless otherwise specified)
SYMBOL
Test Conditions
Min
Typ.
Max.
Unit
Reference Section
Output Voltage
VREF
Tj=25
Line Regulation
Regline
Vcc=12V to 25V
Load Regulation
Regload
Io=1mA to 20mA
Temperature. Stability
Ts
Total Output Variation
VREF
Line, Load, Temperature
Output Noise Voltage
Vn
F=10kHz to 10Hz,Tj=25
Long Term Stability
S
TA=125 ,1000Hrs
Output Short Circuit current
ISC
Oscillator Section
Frequency
,Io=1mA
Tj=25
TA=0
Tj=25
to 70
(RT =6.2k,CT =1.0nF)
4.90
5
5.1
V
2.0
20
mV
3.0
25
0.2
-
4.82
-
5.18
-
50
-
5
-
mV
-85
-180
mA
49
52
55
250
275
1.0
48
225
56
Vcc=12V to 25V
0.2
Frequency Change with Temperature
fosc/ T
TA = 0
0.5
VOSC
Idischg
to 70
to 70
KHz
%
%
1.6
Tj=25
TA = 0
V
-
fosc/ V
Discharge Current
V
-30
Frequency Change with Voltage
Oscillator Voltage Swing(Peak to Peak)
mV
mV/
V
7.8
7.6
8.3
8.8
8.8
mA
2.42
2.50
2.58
V
-0.1
-2.0
Error Amplifier Section
Voltage Feedback Input
VFB
Vo =2.5V
Input Bias Current
IIB
VFB=5.0V
Open Loop Voltage Gain
AVOL
Vo=2V to 4V
65
90
dB
Unity Gain Bandwidth
BW
Tj=25
0.7
1.0
MHz
Power Supply Rejection Ratio
PSRR
Vcc=12V to 25V
60
70
dB
Output Sink Current
Isink
Vo=1.1V,VFB=2.7V
2.0
12
mA
Output Source Current
Isource
Vo=5.0V,VFB=2.3V
-0.5
-1.0
mA
Output Voltage Swing High State
VoH
VFB=2.3V,RL =15K to GND
5.0
6.2
V
Output Voltage Swing Low State
VOL
VFB=2.7V,RL =15K to Vref
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
0.8
1.1
A
V
Any changing of specification will not be informed individual
Page 2 of 10
SPW3842D
High Performance Current Mode
Elektronische Bauelemente
Controlers
Current Sense section
Current Sense Input Voltage gain
Av
Maximum Current Sense Input Threshold Vth
PSRR
Power Supply Rejection Ratio
(Note 3,4)
2.85
3.0
3.15
(Note 3)
0.9
1.0
1.1
VCC= 12 to 25V (Note 3)
Input Bias Current
IIB
Propagation Delay
Tplh(in/out) Current Sense Input to Output
VOL
Isink=20mA
Output Low Voltage
Output High Level
Output Voltage with UVLO Activated
70
Isink=200mA
VOH
VOL
V/V
V
dB
-2
-10
A
150
300
ns
0.1
0.4
V
1.6
2.2
V
Isource=20mA
13
13.5
V
Isource=200mA
12
13.4
V
VCC=6.0V,Isink=1.0mA
0.1
1.1
V
Output Voltage Rise Time
(UVLO)
tr
Tj=25
,CL=1nF
50
150
ns
Output Voltage Fall Time
tr
Tj=25
,CL=1nF
50
150
ns
Under-Voltage Lockout Section
Startup Threshold
Vth
14.5
16
17.5
V
Min. Operating Voltage After Turn-on(VCC)
VCC(min)
8.5
10
11.5
V
Maximum Duty Cycle
DC(MAX)
94
96
Minimum Duty Cycle
DC(MIN)
0
%
0.3
0.5
mA
12
17
mA
PWM Section
%
Total Device
Power Startup Supply Current
ICC+IC
Power Operating Supply Current
ICC+IC
Note 2
Power Supply Zener Voltage
Vz
ICC=25mA
VCC=14V
30
36
V
Note 1: Maximum Package power dissipation limits must be observed.
Note 2: Adject Vcc above the Startup threshold before setting to 15V.
Note 3: This parameter is measured at the latch trip point with VFB=0V.
Note 4: Comparator gain is defined as::
AV
V Output Compensation
V Current Sense Input
Characteristics Curve
ht tp://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 3 of 10
SPW3842D
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
High Performance Current Mode
Controlers
Any changing of specification will not be informed individual
Page 4 of 10
SPW3842D
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
High Performance Current Mode
Controlers
Any changing of specification will not be informed individual
Page 5 of 10
SPW3842D
Elektronische Bauelemente
High Performance Current Mode
Controlers
Application Information
ht tp://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 6 of 10
SPW3842D
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
High Performance Current Mode
Controlers
Any changing of specification will not be informed individual
Page 7 of 10
SPW3842D
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
High Performance Current Mode
Controlers
Any changing of specification will not be informed individual
Page 8 of 10
SPW3842D
High Performance Current Mode
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Controlers
Any changing of specification will not be informed individual
Page 9 of 10
SPW3842D
Elektronische Bauelemente
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
High Performance Current Mode
Controlers
Any changing of specification will not be informed individual
Page 10 of 10