Linear Integrated Circuit
CURRENT−MODE PWM CONTROLLER
The KA3842A KA3842AM are fixe frequency current-mode PWM controller. They are specially designed for OFF−Line and DC−to−DC converter applications 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 totempole output ideally suited for driving a power MOSFET. Protection circuity includes built under−voltage lockout and current limiting. The KA3842A,KA3842AM have UVLO thresholds of 16 V(on) and 10 V (off). The KA3842A ,KA384AM can operate within 100% duty cycle The KA3842A has been proven in applications using the same external components as Motorola's parts,among others .The KA3842AM has been optimized for compatibility with Samsung's parts Many applications can use either The KA3842A KA3842AM have Start-Up Current 0,45 mA KA3842A or KA3842AM
KA3842A KA3842AM
PIN CONNECTION
FEATURES
• • • • Low Start-Up Current Maximum Duty Cycle U/V Lockout With Hysteresis Operating Freguency Up To 500khz
SO-8 DIP-8
ordering information
Device KA3842AM KA3842AMM KA3842AN KA3842AMN Package SO-8 SO-8 DIP-8 DIP-8 Operating temperature 0 to +700C " " "
BLOCK DIAGRAM
Absolute Maximum Ratings
Characteristic Supply Voltage Output Current Analog Inputs Error Amp Output Sink Current Power Dissipation (TA=250C) Symbol VCC IO VI ISINK (E.A) PO Value 30 ±1 −0.3 to VCC 10 1 Unit V A V mA W
Wing Shing Computer Components Co., (H.K.)Ltd. Homepage: http://www.wingshing.com
Tel:(852)2341 9276 Fax:(852)2797 8153 E-mail:
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1
KA3842A/KA3842AM
Electrical characteristics (*VCC=15V, RT=10kΩ , CT=3.3nF, TA=00C to +700C, unless otherwise specified) Characteristics
Reference Section Reference Output Voltege Line Regulation Load Regulation Short Circit Output Current Oscillator Section Oscillation Freguency Frequency Change with Voltage Oscillator Amplitude Error Amplifier Section Input Bias Current Input Voltage Open Loop Voltage Gain Power Supply Rejection Ratio Output Sink Current Output Source Current High Output Voltage Low Output Voltage Current Sense Section Gain Maximum Input Signal Power Supply Rejection Ratio Input Bias Current Output Section Low Output Voltage High Output Voltage Rise Time Fall Time
Symbol
VREF ∆VREF ∆VREF ISC f ∆f/∆VCCF V(OSC) IBIAS VI(E.A) GVO PSRR ISINK ISOURCE VOH VOL GV VI(MAX) PSRR IBIAS VOL VOH tR tF ISINK ISINK ISINK ISINK
Test Condition
TJ = 25°C, IREF = 1 mA 12V ≤ VCC ≤ 25 V 1 mA ≤ IREF ≤ 20mA TA = 25°C TJ = 25°C 12V ≤ VCC ≤ 25 V
Min
4.9
Typ
5.0 6.0 6.0 -100
Max
5.1 20 25 -180 57 1.0
Unit
V mV mA KHz % Vp-p
47
52 0.05 1.6 -0.1
-2 2.58
V1 = 2.5V 2V ≤ V0 ≤ 4V 12V ≤ VCC ≤ 25 V V2 = 2.7V, V1 = 1.1V V2 = 2.3V, V1 = 5V V2 = 2.3V, RL = 15KΩ to GND V2 = 2.7V, RL = 15KΩ to PIN 8 (Note 1 & 2) V1 = 5V (Note1) 12V ≤ VCC ≤ 25 V (Note 1)
2.42 65 60 2 -0.5 5.0
2.5 90 70 7 -1.0 6.0 0.8
µA V dB mA mA V
1.1 3.15 1.1 -10 0.4 2.2 V/V V dB µA
2.85 0.9
3.0 1.0 70 -3.0
= = = =
20 mA 200 mA 20 mA 200 mA
13 12
TJ = 25°C, CL = 1nF (Note 3) TJ = 25°C, CL = 1nF (Note 3) 14.5 8.5
0.08 1.4 13.5 13.0 45 35 16.0 10
V
150 150 17.5 11.5
nS
Under−Voltage Lockout Section Start Theshold VTH(ST) Min. Operating Voltage (After Turn On) PWM Section Max. Duty Cycle Min. Duty Cycle Total Standby Current Start−Up Current Operating Supply Current Zener Voltage VOPR(min)
V V
D(MAX) D(MAX) IST ICC (OPR) VZ V3 = V2 = 0V
95
97
100 % 0
0.17 14 38
0.3 17
mA
30
V
* Adjust VCC above the start threshold before setting at 15V Note 1: Parameter measured at trip point of lath with V2=0 Note 2: Gain defined as A=∆V1/∆V3 ; 0 ≤ V3 ≤ 0.8V Note 3: These parameters, although guaranteed, are not 100% tested in production.
2
KA3842A/KA3842AM
Pad Location
Chip size: 2.38 x 1.63 mm
Pad N 1 2 3 4 Coordinates µm X Y 90 110 1050 110 1310 110 2000 150 Pad N 5 6 7 8 Coordinates µm X Y 1680 1450 1310 1410 815 460 1410 1390
3
KA3842A/KA3842AM
DIM. MIN. A a1 a2 a3 b b1 C c1 D (1) E e e3 F (1) L M S 3.8 0.4 4.8 5.8 1.27 3.81 4.0 1.27 0.6 8 ° (max.) 0.15 0.016 0.65 0.35 0.19 0.25 0.1 mm TYP. MAX. 1.75 0.25 1.65 0.85 0.48 0.25 0.5 0.026 0.014 0.007 0.010 0.004 MIN. inch TYP. MAX. 0.069 0.010 0.065 0.033 0.019 0.010 0.020
OUTLINE AND MECHANICAL DATA
45° (typ.) 5.0 6.2 0.189 0.228 0.050 0.150 0.157 0.050 0.024 0.197 0.244
KA3842AM KA3842AMM
SO8
(1) D and F do not include mold flash or protrusions. Mold flash or potrusions shall not exceed 0.15mm (.006inch).
4
KA3842A/KA3842AM
8
5
–B–
1 4
NOTES: 1. DIMENSION L TO CENTER OF LEAD WHEN FORMED PARALLEL. 2. PACKAGE CONTOUR OPTIONAL (ROUND OR SQUARE CORNERS). 3. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. DIM A B C D F G H J K L M N MILLIMETERS MIN MAX 9.40 10.16 6.10 6.60 3.94 4.45 0.38 0.51 1.02 1.78 2.54 BSC 0.76 1.27 0.20 0.30 2.92 3.43 7.62 BSC ––– 10_ 0.76 1.01 INCHES MIN MAX 0.370 0.400 0.240 0.260 0.155 0.175 0.015 0.020 0.040 .