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부품번호 | UC3842B 기능 |
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기능 | (UC3842B / UC3843B) HIGH PERFORMANCE CURRENT MODE CONTROLLERS | ||
제조업체 | ON Semiconductor | ||
로고 | |||
전체 22 페이지수
UC3842B, UC3843B,
UC2842B, UC2843B
High Performance
Current Mode Controllers
The UC3842B, UC3843B series are high performance fixed
frequency current mode controllers. They are specifically designed for
Off−Line and DC−DC converter applications offering the designer a
cost−effective solution with minimal 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 undervoltage lockouts each with hysteresis, cycle−by−cycle
current limiting, programmable output deadtime, and a latch for single
pulse metering.
These devices are available in an 8−pin dual−in−line and surface
mount (SOIC−8) plastic package as well as the 14−pin plastic surface
mount (SOIC−14). The SOIC−14 package has separate power and
ground pins for the totem pole output stage.
The UCX842B has UVLO thresholds of 16 V (on) and 10 V (off),
ideally suited for off−line converters. The UCX843B is tailored for
lower voltage applications having UVLO thresholds of 8.5 V (on) and
7.6 V (off).
Features
• Trimmed Oscillator for Precise Frequency Control
• Oscillator Frequency Guaranteed at 250 kHz
• Current Mode Operation to 500 kHz
• 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 Startup and Operating Current
• This is a Pb−Free and Halide−Free Device
VCC 7(12)
Vref
8(14)
R
5.0V
Reference
VCC
Undervoltage
Lockout
Vref
R Undervoltage
Lockout
VC
7(11)
RT/CT
Oscillator
Output
4(7)
Voltage
Feedback
+
Latching
PWM
6(10)
Power
Ground
Input -
5(8)
2(3)
Output
Compensation
1(1)
Error
Amplifier
GND 5(9)
Current
Sense
3(5) Input
Pin numbers in parenthesis are for the D suffix SOIC−14 package.
Figure 1. Simplified Block Diagram
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8
1
14
1
8
1
PDIP−8
N SUFFIX
CASE 626
SOIC−14
D SUFFIX
CASE 751A
SOIC−8
D1 SUFFIX
CASE 751
PIN CONNECTIONS
Compensation 1
Voltage Feedback 2
Current Sense 3
RT/CT 4
8 Vref
7 VCC
6 Output
5 GND
(Top View)
Compensation 1
NC 2
Voltage Feedback 3
NC 4
Current Sense 5
NC 6
RT/CT 7
14 Vref
13 NC
12 VCC
11 VC
10 Output
9 GND
8 Power Ground
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 17 of this data sheet.
DEVICE MARKING INFORMATION
See general marking information in the device marking
section on page 19 of this data sheet.
© Semiconductor Components Industries, LLC, 2013
September, 2013 − Rev. 17
1
Publication Order Number:
UC3842B/D
UC3842B, UC3843B, UC2842B, UC2843B
ELECTRICAL CHARACTERISTICS (VCC = 15 V [Note 7], RT = 10 k, CT = 3.3 nF. For typical values TA = 25°C, for min/max values
TA is the operating ambient temperature range that applies [Note 8], unless otherwise noted.)
UC284XB, UC2843D
UC384XB, XBV
Characteristics
Symbol Min Typ Max Min Typ Max Unit
CURRENT SENSE SECTION
Current Sense Input Voltage Gain (Notes 5 and 6)
UC2843D, UC284XB, UC384XB
UC384XBV
AV
V/V
2.85 3.0 3.15 2.85 3.0 3.15
− − − 2.85 3.0 3.25
Maximum Current Sense Input Threshold (Note 5)
UC2843D, UC284XB, UC384XB
UC384XBV
Vth
0.9 1.0 1.1 0.9 1.0 1.1
− − − 0.85 1.0 1.1
V
Power Supply Rejection Ratio (VCC = 12 V to 25 V, Note 5)
Input Bias Current
Propagation Delay (Current Sense Input to Output)
OUTPUT SECTION
Output Voltage
Low State (ISink = 20 mA)
(ISink = 200 mA)
High State (ISource = 20 mA)
(ISource = 200 mA)
UC284XB, UC384XB
UC384XBV, UC2843D
UC284XB, UC384XB
UC384XBV, UC2843D
Output Voltage with UVLO Activated (VCC = 6.0 V, ISink = 1.0 mA)
Output Voltage Rise Time (CL = 1.0 nF, TJ = 25°C)
Output Voltage Fall Time (CL = 1.0 nF, TJ = 25°C)
UNDERVOLTAGE LOCKOUT SECTION
Startup Threshold (VCC)
UCX842B, BV
UCX843B, BV, D
PSRR
IIB
tPLH(In/Out)
VOL
VOH
VOL(UVLO)
tr
tf
Vth
−
−
−
−
−
−
13
−
12
−
−
−
15
7.8
70
− 2.0
150
−
−10
300
0.1 0.4
1.6 2.2
−−
13.5 −
−−
13.4 −
0.1 1.1
50 150
50 150
16 17
8.4 9.0
− 70 −
− − 2.0 −10
− 150 300
− 0.1
− 1.6
− 1.6
13 13.5
12.9 13.5
12 13.4
0.4
2.2
2.3
−
−
−
− 0.1 1.1
− 50 150
− 50 150
14.5 16 17.5
7.8 8.4 9.0
dB
mA
ns
V
V
ns
ns
V
Minimum Operating Voltage After Turn−On (VCC)
VCC(min)
V
UCX842B, BV
9.0 10 11 8.5 10 11.5
UCX843B, BV, D
7.0 7.6 8.2 7.0 7.6 8.2
PWM SECTION
Duty Cycle
Maximum UC284XB, UC384XB, UC2843D
Maximum UC384XBV
Minimum
%
DC(max) 94 96 − 94 96 −
− − − 93 96 −
DC(min)
−
−
0
−
−
0
TOTAL DEVICE
Power Supply Current
Startup (VCC = 6.5 V for UCX843B, UC2843D
Startup VCC 14 V for UCX842B, BV)
(Note 7)
ICC + IC
mA
− 0.3 0.5 − 0.3 0.5
− 12 17 − 12 17
Power Supply Zener Voltage (ICC = 25 mA)
VZ 30 36 − 30 36
5. This parameter is measured at the latch trip point with VFB = 0 V.
6. Comparator gain is defined as: AV
DV Output Compensation
DV Current Sense Input
7. Adjust VCC above the Startup threshold before setting to 15 V.
8. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.
Tlow = 0°C for UC3842B, UC3843B; −25°C for UC2842B, UC2843B; −40°C for UC3842BV, UC3843BV, UC2843D
Thigh = +70°C for UC3842B, UC3843B; +85°C for UC2842B, UC2843B, UC2843D; +105°C for UC3842BV, UC3843BV
−
V
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4
4페이지 UC3842B, UC3843B, UC2842B, UC2843B
0
ÄÄÄÄÄÄÄÄÄVCC
Source Saturation
VCC = 15 V
(Load to Ground) 80 ms Pulsed Load
ÄÄÄÄÄÄÄÄÄÄÄÄÄ-1.0 TA=25°C
120 Hz Rate
ÄÄÄÄ ÄÄÄÄÄ- 2.0
ÄÄÄÄTA = - 55°C
ÄÄÄÄ3.0
ÄÄÄTA = - 55°C
ÄÄÄ ÄÄÄ2.0
TA = 25°C
ÄÄÄÄ ÄÄÄ1.0 Sink Saturation
ÄÄÄÄ ÄÄ(Load to VCC)
GND
0
0 200 400 600 800
90%
10%
VCC = 15 V
CL = 1.0 nF
TA = 25°C
IO, OUTPUT LOAD CURRENT (mA)
50 ns/DIV
Figure 14. Output Saturation Voltage
versus Load Current
Figure 15. Output Waveform
25
VCC = 30 V
CL = 15 pF
TA = 25°C
100 ns/DIV
Figure 16. Output Cross Conduction
20
15
ÄÄÄÄ10
RT = 10 k
ÄÄÄÄCT = 3.3 nF
5 VFB = 0 V
ÄÄÄÄISense = 0 V
ÄÄÄÄTA = 25°C
0
0 10 20 30 40
VCC, SUPPLY VOLTAGE (V)
Figure 17. Supply Current versus Supply Voltage
PIN FUNCTION DESCRIPTION
8−Pin 14−Pin
Function
1 1 Compensation
23
Voltage
Feedback
35
Current
Sense
47
RT/CT
5
6 10
GND
Output
7 12
8 14
8
11
9
2,4,6,1
3
VCC
Vref
Power
Ground
VC
GND
NC
Description
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.
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 to 500 kHz 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 1.0 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.
This pin is a separate power ground return that is connected back to the power source. It is used
to reduce the effects of switching transient noise on the control circuitry.
The Output high state (VOH) is set by the voltage applied to this pin. With a separate power
source connection, it can reduce the effects of switching transient noise on the control circuitry.
This pin is the control circuitry ground return and is connected back to the power source ground.
No connection. These pins are not internally connected.
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7
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구매 문의 | 일반 IC 문의 : 샘플 및 소량 구매 ----------------------------------------------------------------------- IGBT, TR 모듈, SCR 및 다이오드 모듈을 포함한 광범위한 전력 반도체를 판매합니다. 전력 반도체 전문업체 상호 : 아이지 인터내셔날 사이트 방문 : [ 홈페이지 ] [ 블로그 1 ] [ 블로그 2 ] |
부품번호 | 상세설명 및 기능 | 제조사 |
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DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |