|
|
UC3842AのメーカーはFairchild Semiconductorです、この部品の機能は「(UC3842A / UC3843A) SMPS Controller」です。 |
部品番号 | UC3842A |
| |
部品説明 | (UC3842A / UC3843A) SMPS Controller | ||
メーカ | Fairchild Semiconductor | ||
ロゴ | |||
このページの下部にプレビューとUC3842Aダウンロード(pdfファイル)リンクがあります。 Total 8 pages
UC3842A/UC3843A
SMPS Controller
www.fairchildsemi.com
Features
• Low Start Current 0.2mA (typ)
• Operating Range Up To 500KHz
• Cycle by Cycle Current Limiting
• Under Voltage Lock Out With Hysteresis
• Short Shutdown Delay Time: typ.100ns
• High Current Totem-pole Output
• Output Swing Limiting: 22V
Description
The UC3842A/UC3843A are fixed PWM controller for Off-
Line and DC to DC converter applications. The internal cir-
cuits include UVLO, low start up current circuit, tempera-
ture compensated reference, high gain error amplifier,
current sensing comparator, and high current totem-pole out-
put for driving a POWER MOSFET. Also UC3842A/
UC3843A provide low start up current below 0.3mA and
short shutdown delay time typ. 100ns. The UC3842A has
UVLO threshold of 16V(on) and 10V(off). The UC3843A is
8.4V(on) and 7.6V(off). The UC3842A and UC3843A can
operate within 100% duty cycle.
8-DIP
Internal Block Diagram
8-SOP
1
1
VREF 8
Internal
Bias
5V
VREF
SET/
RESET
Good LOGIC
UVLO
VFB 2
COMP 1
1/2VREF
Error Amp
+
-
1/3
1V
C.S PWM
Comp. LATCH
R
S
C.S 3
T
RT/CT 4
OSCILLATOR
7 VCC
29V
5 GND
7
PWR
VC
22V 6 OUTPUT
5
PWR
GND
©2000 Fairchild Semiconductor International
Rev. 5.0
1 Page Electrical Characteristics (Continued)
(VCC = 15V, RT = 10KΩ, CT = 3.3nF, TA = 0°C to + 70°C, Unless otherwise specified)
Parameter
Symbol
Conditions
ERROR AMPLIFIER SECTION
Input Voltage
VI TPIN1 = 2.5V
Input Bias Current
IBIAS
-
Open Loop Gain
GVO
VO = 2V to 4V (NOTE 1)
Unity Gain Bandwidth
GBW TJ= 25°C (NOTE 1)
PSRR
PSRR VCC = 12V to 25V (NOTE 1)
Output Sink Current
ISINK
VPIN2 = 2.7V
VPIN1 = 1.1V
Output Source Current
ISOURCE
VPIN2 = 2.3V
VPIN1 = 5.0V
Output High Voltage
VOH
VPIN2 = 2.3V
R1 = 15KΩ to GND
Output Low Voltage
VOL
VPIN2 = 2.7V
R1 = 15KΩ to Pin8
OUTPUT SECTION
Output Low Level
VOL
ISINK = 20mA
ISINK = 200mA
Output High Level
VOH
ISOURCE = 20mA
ISOURCE = 200mA
Rise Time
tR TJ = 25°C, C1 = 1nF (NOTE 1)
Fall Time
tF TJ = 25°C, C1 = 1nF (NOTE 1)
Output Voltage Swing Limit
VOLIM VCC = 27V, C1 = 1nF
UNDER VOLTAGE LOCKOUT SECTION
Start Threshold
UC3842A
VTH
UC3843A
Min. Operating Voltage
( After turn on )
UC3842A
VTL
UC3843A
PWM SECTION
Maximum Duty Cycle
DMAX UC3842A/UC3843A
Minimum Duty Cycle
DMIN
-
TOTAL STANDBY CURRENT
Start-Up Current
IST
-
Operating Supply Current
ICC VPIN2 = VPIN3 = 0V
VCC Zener Voltage
VZ ICC = 25mA
* Adjust VCC above the start threshold before setting at 15V
Notes :
1. These parameters, although guaranteed, are not 100% tested in production.
2. Parameter measured at trip point of latch with V2 = 0V.
3. Gain defined as: GV = ∆VPIN1∆VPIN3(VPIN3 = 0 to 0.8V)
UC3842A/UC3843A
Min. Typ. Max. Unit
2.42 2.50 2.58 V
- -0.3 - 2 uA
65 90 - dB
0.7 1
- MHz
60 70 - dB
2 6 - mA
-0.5 -0.8 - mA
56 -V
- 0.8 1.1 V
- 0.1 0.4 V
- 1.5 2.2 V
13 13.5 -
V
12 13.5 -
V
- 40 100 ns
- 40 100 ns
- 22 -
V
15 16 17
7.8 8.4 9.0
9 10 11
7.0 7.6 8.2
V
V
V
V
94 96 100 %
- - 0%
- 0.2 0.4 mA
- 11 17 mA
- 29 -
V
3
3Pages UC3842A/UC3843A
Ordering Information
Product Number
UC3842AN
UC3842AD
UC3843AN
UC3843AD
Package
8 DIP
8 SOP
8 DIP
8 SOP
Operating Temperature
0 ~ + 70°C
6
6 Page | |||
ページ | 合計 : 8 ページ | ||
|
PDF ダウンロード | [ UC3842A データシート.PDF ] |
データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。 |
部品番号 | 部品説明 | メーカ |
UC3842 | Current Mode PWM Controller (Rev. C) | Texas Instruments |
UC3842 | Current-mode PWM controller | Philips |
UC3842 | SMPS Controller | Fairchild |
UC3842 | CURRENTMODE PWM CONTROLLER | ST Microelectronics |