PL384XAP8 [CYSTEKEC]
High Performance Current Mode PWM Controllers; 高性能电流模式PWM控制器
| 型号： | PL384XAP8 |
| 厂家： | 
CYSTECH ELECTONICS CORP. |
| 描述： | High Performance Current Mode PWM Controllers |
| 文件： | 总15页 (文件大小：281K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 1/15
High Performance Current Mode PWM Controllers
PL384XAP8
Description
The PL384XAP8 family of control ICs provides the necessary features to implement off-line or DC to DC fixed
frequency current mode control schemes with a minimal external parts count. Internally implemented circuits
include a trimmed oscillator for precise duty cycle control, under voltage lockout featuring start-up current less than
1.0mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM
comparator which also provides current limit control, and a totem pole output stage designed to source or sink high
peak current. The output stage, suitable for driving N-channel MOSFETs, is low in the off-state.
Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle
ranges. The PL3842A and PL3844A have UVLO thresholds of 16V (on) and 10V (off), ideally suited off-line
applications. The corresponding thresholds for the PL3843A and PL3845A are 8.5V and 7.9V. The PL3842A and
PL3843A can operate to duty cycles approaching 100%. A range of the zero to <50% is obtained by the PL3844A
and PL3845A by the addition of an internal toggle flip flop which blanks the output off every other clock cycle.
Features
• Trimmed oscillator for precise frequency control
• Oscillator frequency guaranteed at 250 kHz
• Current mode operation to 500kHz
• Automatic feed forward compensation
• Latching PWM for cycle-by-cycle current limiting
• Internally trimmed reference with undervoltage lockout
• High current totem pole output
• Undervoltage lockout with hysteresis
• Low start-up and operating current
Block Diagram
( toggle flip flop used only in PL3844A and PL3845A)
VI
7
UVLO
34V
8
5V
REF
VREF
5V50mA
S/R
5
GROUND
INTERNAL
BIAS
2.50V
VREF GOOD
LOGIC
6
OUTPUT
4
T
RT/CT
OSC
ERROR AMP.
S
2R
2
1
VFB
PWM
R
1V
LATCH
R
CURRENT
SENSE
COMPARATOR
COMP
3
CURRENT
SENSE
PL3842A
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 2/15
Absolute Maximum Ratings
Symbol Parameter
Value
Unit
V
VI
VI
IO
Supply Voltage (low impedance source)
30
Supply Voltage (Ii<30mA)
Output Current
Self Limiting
A
± 1
5
EO
Output Energy (capacitive load)
µJ
Analog Inputs (pins 2, 3)
-0.3 to 5.5
10
V
Error Amplifier Output Sink Current
Power Dissipation at Tamb≤ 25℃
mA
W
Ptot
1.25
Tstg Storage Temperature Range
-65 to +150
-40 to +150
300
℃
℃
℃
TJ
Junction Operating Temperature
Lead Temperature (soldering 10s)
TL
Note : All voltages are with respect to pin 5, all currents are positive into the specified terminal.
Pin Connection (top view)
COMP
VREF
VFB
ISENSE
RT/CT
VCC
OUTPUT
GROUND
Pin Functions
No Function
Description
1
2
COMP
VFB
This pin is the Error Amplifier output and is made available for loop compensation.
This is the inverting input of the Error Amplifier. It is normally connected to the switching
power supply output through a resistor divider.
3
ISENSE
A voltage proportional to inductor current is connected to this input. The PWM uses this
information to terminate the output switch conduction.
4
RT/CT
The oscillator frequency and maximum output duty cycle are programmed by connecting
resistor RT to VREF and capacitor CT to ground. Operation to 500kHz is possible.
5
6
GROUND This pin is the combined control circuitry and power ground.
OUTPUT
This output directly drives the gate of a power MOSFET. Peak currents up to 1A are sourced
and sunk by this pin.
7
8
VCC
VREF
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.
Thermal Data
Symbol
Rth, j-amb
Description
Thermal Resistance, junction to ambient
Value
100
Unit
℃/W
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 3/15
Electrical Characteristics (〔note 1〕Unless otherwise stated, these specifications apply for
0≤Tamb≤70℃,Vi=15V(note 5),RT=10k,CT=3.3nF)
Parameter
Test Conditions
Symbol
Min. Typ. Max.
Unit
Reference Section
Tj=25℃,IO=1mA
Output Voltage
VREF
∆VREF
4.9
5.0
2
5.1
20
V
mV
Line Regulation
12V ≤ VI≤ 25V
-
Load Regulation
Temperature Stability
Total Output Variation
Output Noise Voltage
Long Term Stability
Output Short Circuit
1mA ≤ IO ≤ 20mA
(Note 2)
Line, Load, Temperature
10Hz ≤ f ≤10kHz,Tj=25℃ (note 2)
∆VREF
-
-
3
25
mV
mV/℃
V
µV
mV
mA
∆VREF / ∆T
0.2
-
50
5
-
4.82
5.18
-
-
-
25
eN
Tamb=125℃, 1000 Hrs (note 2)
ISC
-30 -100 -180
Oscillator Section
Tj=25℃
49
48
52
-
55
56
kHz
kHz
kHz
TA= 0 to 70 ℃
Tj=25℃(RT=6.2k,CT=1nF)
VCC=12V to 25V
TA= 0 to 70 ℃
Peak to peak
Frequency
fosc
225- 250 275
Frequency Change with Volt
Frequency Change with Temp
Oscillator Voltage Swing
∆fosc/∆V
∆fosc/∆T
Vosc
-
-
-
0.2 1.0
%
%
V
0.5 1.0
1.6
-
TJ=25℃
TA= 0 to 70 ℃
7.8
8.3 8.8
mA
Discharge Current (Vosc=2V)
Idischg
7.6
-
8.8
mA
Error Amp Section
Input Voltage
VPIN 1=2.5V
V2
Ib
2.42 2.50 2.58
V
µA
dB
MHz
dB
mA
mA
V
Input Bias Current
AVOL
VFB=5V
-
65
0.7
60
2
-0.1 -2
90
1
70
12
-1
-
-
-
-
-
-
2V ≤ Vo ≤ 4V
TJ = 25℃
Unity Gain Bandwidth
Power Supply Rejec. Ratio
Output Sink Current
Output Source Current
VOUT High
BW
PSRR
IO
VI = 12V to 25V
VPIN 2 = 2.7V, VPIN 1 = 1.1V
VPIN 2 = 2.3V, VPIN 1 = 5V
VPIN 2 = 2.3V, RL = 15kΩ to ground
VPIN 2 = 2.7V, RL = 15kΩ to Pin 8
IO
-0.5
5
-
6.2
0.8 1.1
VOUT Low
V
Current Sense Section
Gain
(note 3 & 4)
VPIN 1 = 5V (note 3)
12V ≤ VI ≤ 25V
GV
V3
SVR
Ib
2.85
3
1
3.15
1.1
-
V/V
V
dB
µA
ns
Maximum Input Signal
Supply Voltage Rejection
Input Bias Current
Delay to Output
0.9
-
-
-
70
-2
-10
150 300
Output Section
Output Low Level
ISINK = 20mA
VOL
-
-
0.1 0.4
1.6 2.2
V
V
V
V
V
ns
ns
ISINK = 200mA
Output High Level
ISOURCE = 20mA
ISOURCE = 200mA
VCC = 6V, ISINK = 1mA
Tj=25℃, CL=1nF (note 2)
Tj=25℃, CL=1nF (note 2)
VOH
13 13.5
12 13.5
-
-
UVLO Saturation
Rise Time
Fall Time
VOLS
tr
tf
-
-
-
0.1 1.1
50 150
50 150
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 4/15
Electrical Characteristics (continued)
Parameter
Test Conditions
Symbol
Min. Typ. Max. Unit
Undervoltage Lockout Section
Start Threshold
PL3842A/PL3844A
PL3843A/PL3845A
14.5 16 17.5
7.8 8.4 9.0
V
V
Min Operating Voltage
After Turn-on
PL3842A/PL3844A
8.5
10 11.5
V
PL3843A/PL3845A
7.0 7.6 8.2
PWM Section
Maximum Duty Cycle
PL3842A/PL3843A
PL3844A/PL3845A
94
47
-
96 100
%
%
%
48
-
50
0
Minimum Duty Cycle
Total Standby Current
Start-up Current
VI=6.5V for PL3843A/45A
VI=14V for PL3842A/44A
VPIN 2 = VPIN 3 = 0V
Ist
-
-
-
0.17 0.3
0.17 0.3
mA
mA
mA
V
Operating Supply Current
Zener Voltage
II
VIZ
12
38
17
-
II = 25 mA
30
Notes: 1. Max. package power dissipation limits must be respected; low duty cycle pulse techniques are used during test
maintain Tj as close to Tamb as possible.
2.These parameters, although guaranteed, are not 100% tested in production.
3.Parameter measured at trip point of latch with VPIN 2= 0 .
4.Gain defined as:
∆VPIN 1
, 0 ≤ VPIN 3 ≤ 0.8V
A=
∆VPIN 3
5. Adjust VI above the start threshold before setting at 15V.
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 5/15
Figure 1: Open Loop Test Circuit
VREF
RT
4.7k
2N2222
100k
A
VI
VREF
0.1uF
COMP
VFB
8
1
7
VI
ERROR AMP.
ADJUST
2
1W
1k
1k
0.1uF
ISENSE
RT/CT
ISENSE
OUTPUT
GROUND
3
4
6
ADJUST
OUTPUT
GROUND
5k
4.7k
5
CT
High peak currents associated with capacitive loads necessitate careful grounding techniques. Timing and bypass
capacitors should be connected close to pin 5 in a single point ground. The transistor and 5kΩ potentiometer are
used to sample the oscillator waveform and apply an adjustable ramp to pin 3.
Figure 3:Output Dead-Time vs Oscillator Frequency
Figure 2:Timing Resistor vs Oscillator Frequency
100
10
1
100
10
1
CT=100pF
200pF
CT=2nF
CT=1nF
CT=10nF
CT=5nF
500pF
CT=500p
10nF
5nF
CT=200pF
CT=100pF
2nF
1nF
Vi=15V
TA=25
Vi=15V,TA=25
10
100
Oscillator Frequency---fosc(kHz)
1000
10
100
1000
Oscillator Frequency---fosc(kHz)
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 6/15
Figure 4:Oscillator Discharge Current vs Temperature
Figure 5:Maximum Output Duty Cycle vs Timing
Resistor
9
8.5
8
100
90
80
70
60
50
40
Vi=15V
VOSC=2V
Idischg=7.5mA
Idischg=8.8m
Vi=15V
CT=3.3nF
TA=25℃
7.5
7
-50
-25
0
25
50
75
100
125
0.1
1
10
Ambient Temperature---TA(℃)
Timing Resistor---RT(kΩ)
Figure 6:Error Amp Open-Loop Gain vs Frequency
Figure 7:Error Amp Phase vs Frequency
180
100
80
60
40
20
0
Vi=15V,Vo=2 to
4V
RL=100k,TA=25
Vi=15V,Vo=2 to 4V
RL=100l,TA=25℃
150
120
90
60
30
0
-20
10
100
1000 10000 100000 100000 1E+07
0
10
100
1000 10000 100000 100000 1E+07
Frequency---f(Hz)
Frequency---f(Hz)
0
Figure 8:Current Sense Input Threshold vs Error Amp
Output Voltage
Figure 9:Reference Short Circuit Current vs Temperature
1.2
1
110
Vi=15V
Vi=15V
100
90
80
70
60
50
RL≦0.1Ω
TA=125℃
0.8
0.6
0.4
0.2
0
TA=25℃
TA=-40℃
0
2
4
6
8
-50
-25
0
25
50
75
100
125
Error Amp Output Voltage---Vo(V)
Ambient Temperature---TA(℃)
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 7/15
Figure 10.Oscillator and Output Waveforms
Vi
7
CT
8
5V REG
OUTPUT
PWM
6
OUTPUT
RT
CLOCK
OSCILLATOR
LARGE RT/SMALL CT
4
ID
CT
CT
OUTPUT
5
SMALL RT/LARGE CT
GND
Figure 11:Error Amp Configuration
2.5V
1mA
2
VFB
Zi
1
COMP
Zf
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 8/15
Figure 12:Under Voltage Lockout
Figure 13:Current Sense Circuit
ERROR
AMP
2R
R
1V
CURRENT
SENSE
Is
COMPARATOR
1
COMP
R
3
CURRENT
SENSE
Rs
C
5
GND
Peak Current (is) is determined by the formula
IS max ≈1.0V/Rs
A small RC filter may be required to suppress switch transients.
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 9/15
Figure 14:Slope Compensation Techniques.
VREG
VREG
8
8
Is
RT
RT/CT
RT
RT/CT
Is
4
4
3
CT
CT
Rslope
R1
Rslope
R1
ISENSE
3
ISENSE
5
5
Rs
GND
GND
Rs
Figure 15:Isolated MOSFET Drive and Current Transformer Sensing
Vin
VCC
7
ISOLATION
BOUNDARY
5.0Vref
VGS Waveforms
Q1
0
0
6
50% DC
25% DC
S
V(pin 1)-1.4
3Rs
Ns
Np
Ipk
Q
R
COMP/LATCH
R
3
C
Rs
Ns
Np
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 10/15
Figure 16:Latched Shutdown
4
OSC
8
R
BIAS
R
1mA
2R
2
EA
R
1
5
2N
3905
2N
3903
SCR must be selected for a holding current of less than 0.5mA at TA(min).
The simple two transistor circuit can be used in place of the SCR as shown. All resistors are 10K.
Figure 17:External Clock Synchronization
8
R
R
BIAS
OSC
RT
CT
4
+
EXTERNAL
SYNC INPUT
μ
F
0.01
2R
Ω
47
2
1
R
5
The diode clamp is required if the Sync amplitude is large enough to cause
the bottom side of CT to go more than 300mV below ground.
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 11/15
Figure 18: Error Amplifier Compensation
+
From Vo
2.5V
1mA
Ri
2R
R
2
1
Cf
EA
Rd
Rf
5
Error Amp compensation circuit for stabilizing any current -mode topology except
for boost and flyback converters operating with continuous inductor current.
+
From Vo
2.5V
1mA
Rp
Cp
2R
Ri
2
1
Cf
EA
R
Rd
Rf
5
Error Amp compensation circuit for stabilizing current--mode boost and flyback
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 12/15
Figure 19:External Duty Cycle Clamp and Multi Unit Synchronization
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 13/15
Figure 20:Soft-Start Circuit
5Vref
8
4
2
R
R
BIAS
OSC
+
1mA
S
2R
Q
R
EA
R
1V
Ω
1M
1
5
C
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 14/15
Figure 21:Soft-Start and Error Amplifier Output Duty Cycle Clamp.
Vcc
Vin
7
5Vref
8
4
2
R
R
BIAS
OSC
7
6
Q1
+
5
1mA
Vclamp
S
2R
Q
R
EA
R
1V
Comp/Latch
R2
R1
3
1
5
C
BC109
Rs
VCLAMP
Rs
-
R1
R1
+
<1V
where 0< VCLAMP
Ipk(max)
=
VCLAMP
=
2
R
PL384XAP8
CYStek Product Specification
Spec. No. : C510P8-A
Issued Date : 2003.08.12
Revised Date :
CYStech Electronics Corp.
Page No. : 15/15
DIP-8P Dimension
Marking :
6
3
5
4
8
1
7
2
A
384XA
B
J
F
α1
DIP-8P Plastic Package
K
L
E
C
G
CYStek Package Code : P8
D H
M
I
*:Typical
Inches
Millimeters
Inches
Min. Max.
Millimeters
DIM
DIM
Min.
Max.
Min.
Max.
6.40
9.32
*1.52
*1.27
*0.99
3.35
3.55
Min.
Max.
0.53
2.79
7.74
*3.00
8.81
0.381
97°
A
B
C
D
E
F
0.2480 0.2520
0.3630 0.3670
6.29
9.22
-
H
I
0.0150 0.0210
0.0898 0.1098
0.2950 0.3050
0.38
2.28
7.49
-
-
-
-
*0.0600
*0.0500
*0.0390
J
-
K
L
-
*0.1181
-
0.3370 0.7470
0.0090 0.0150
8.56
0.229
94°
0.1280 0.1320
0.1250 0.1400
3.25
3.17
M
α1
G
94°
97°
Notes : 1.Controlling dimension : millimeters.
2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.
3.If there is any question with packing specification or packing method, please contact your local CYStek sales office.
Material :
• Lead : 42 Alloy ; solder plating
• Mold Compound : Epoxy resin family, flammability solid burning class:UL94V-0
Important Notice:
• All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek.
• CYStek reserves the right to make changes to its products without notice.
• CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems.
• CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance.
PL384XAP8
CYStek Product Specification
相关型号：
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