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UC2842AのメーカーはMotorola Semiconductorsです、この部品の機能は「(UC2842A / UC2843A) HIGH PERFORMANCE CURRENT MODE CONTROLLERS」です。 |
部品番号 | UC2842A |
| |
部品説明 | (UC2842A / UC2843A) HIGH PERFORMANCE CURRENT MODE CONTROLLERS | ||
メーカ | Motorola Semiconductors | ||
ロゴ | |||
このページの下部にプレビューとUC2842Aダウンロード(pdfファイル)リンクがあります。 Total 14 pages
Order this document by UC3842A/D
High Performance
Current Mode Controllers
The UC3842A, UC3843A series of high performance fixed frequency
current mode controllers are specifically designed for off–line and dc–to–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 plastic package as
well as the 14–pin plastic surface mount (SO–14). The SO–14 package has
separate power and ground pins for the totem pole output stage.
The UCX842A has UYLO thresholds of 16 V (on) and 10 V (off), ideally
suited for off–line converters. The UCX843A is tailored for lower voltage
applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off).
• Trimmed Oscillator Discharge Current for Precise Duty Cycle Control
• 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
• Direct Interface with Motorola SENSEFET Products
Vref
8(14)
RTCT
4(7)
Voltage
Feedback
Input
2(3)
Output
Compensation
1(1)
Simplified Block Diagram
VCC 7(12)
R
5.0V
Reference
VCC
Undervoltage
Lockout
R
Vref
Undervoltage
Lockout
Oscillator
+
–
Error
Amplifier
Latching
PWM
Gnd 5(9)
Pin numbers in parenthesis are for the D suffix SO–14 package.
VC
7(11)
Output
6(10)
Power
Ground
5(8)
Current
Sense
3(5) Input
UC3842A, 43A
UC2842A, 43A
HIGH PERFORMANCE
CURRENT MODE
CONTROLLERS
N SUFFIX
PLASTIC PACKAGE
CASE 626
D SUFFIX
PLASTIC PACKAGE
CASE 751A
(SO–14)
8
1
14
1
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
Device
Operating
Temperature Range
Package
UC3842AD
SO–14
UC3843AD
UC3842AN
TA = 0° to +70°C
SO–14
Plastic
UC3843AN
Plastic
UC2842AD
SO–14
UC2843AD
TA = – 25° to +85°C
UC2842AN
SO–14
Plastic
UC2843AN
Plastic
MOTOROLA ANALOG IC DEVICE DATA
© Motorola, Inc. 1996
Rev 1
1
1 Page UC3842A, 43A UC2842A, 43A
ELECTRICAL CHARACTERISTICS (VCC = 15 V, [Note 2], RT = 10 k, CT = 3.3 nF, TA = Tlow to Thigh [Note 3],
unless otherwise noted.)
UC284XA
UC384XA
Characteristics
Symbol Min Typ Max Min Typ Max
ERROR AMPLIFIER SECTION
Voltage Feedback Input (VO = 2.5 V)
VFB 2.45 2.5 2.55 2.42 2.5 2.58
Input Bias Current (VFB = 2.7 V)
IIB – –0.1 –1.0 – –0.1 –2.0
Open Loop Voltage Gain (VO = 2.0 V to 4.0 V)
Unity Gain Bandwidth (TJ = 25°C)
AVOL 65 90 – 65 90 –
BW 0.7 1.0 – 0.7 1.0 –
Power Supply Rejection Ratio (VCC = 12 V to 25 V)
PSRR
60 70
–
60 70
–
Output Current
Sink (VO = 1.1 V, VFB = 2.7 V)
Source (VO = 5.0 V, VFB = 2.3 V)
ISink
2.0 12
– 2.0 12
–
ISource
–0.5 –1.0
–
–0.5 –1.0
–
Output Voltage Swing
High State (RL = 15 k to ground, VFB = 2.3 V)
Low State (RL = 15 k to Vref, VFB = 2.7 V)
VOH
VOL
5.0 6.2 – 5.0 6.2 –
– 0.8 1.1 – 0.8 1.1
CURRENT SENSE SECTION
Current Sense Input Voltage Gain (Notes 4 & 5)
AV 2.85 3.0 3.15 2.85 3.0 3.15
Maximum Current Sense Input Threshold (Note 4)
Vth 0.9 1.0 1.1 0.9 1.0 1.1
Power Supply Rejection Ratio
VCC = 12 to 25 V (Note 4)
PSRR
– 70 –
– 70 –
Input Bias Current
IIB – –2.0 –10 – –2.0 –10
Propagation Delay (Current Sense Input to Output) tPLH(in/out)
–
150 300
–
150 300
OUTPUT SECTION
Output Voltage
Low State (ISink = 20 mA)
Low State (ISink = 200 mA)
High State (ISink = 20 mA)
High State (ISink = 200 mA)
Output Voltage with UVLO Activated
VCC = 6.0 V, ISink = 1.0 mA
VOL
VOH
– 0.1 0.4
– 1.6 2.2
13 13.5
–
12 13.4
–
VOL(UVLO)
–
0.1 1.1
– 0.1 0.4
– 1.6 2.2
13 13.5
–
12 13.4
–
– 0.1 1.1
Output Voltage Rise Time (CL = 1.0 nF, TJ = 25°C)
tr
–
50 150
–
50 150
Output Voltage Fall Time (CL = 1.0 nF, TJ = 25°C)
tf
–
50 150
–
50 150
UNDERVOLTAGE LOCKOUT SECTION
Startup Threshold
UCX842A
UCX843A
Vth
15 16 17 14.5 16 17.5
7.8 8.4 9.0 7.8 8.4 9.0
Minimum Operating Voltage After Turn–On
UCX842A
UCX843A
VCC(min)
9.0 10 11 8.5 10 11.5
7.0 7.6 8.2 7.0 7.6 8.2
PWM SECTION
Duty Cycle
Maximum
Minimum
DCmax 94 96 – 94 96
DCmin
–
–
0
–
–
TOTAL DEVICE
Power Supply Current (Note 2)
Startup:
ICC
(VCC = 6.5 V for UCX843A,
(VCC = 14 V for UCX842A) Operating
– 0.5 1.0 –
– 12 17 –
Power Supply Zener Voltage (ICC = 25 mA)
VZ 30 36 – 30
NOTES: 2. Adjust VCC above the Startup threshold before setting to 15 V.
3. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible
Tlow = –20°C for UC3842A, UC3843A
Thigh = +70°C for UC3842A, UC3843A
Tlow = –25°C for UC2842A, UC2843A
Thigh = +85°C for UC2842A, UC2843A
4. This parameter is measured at the latch trip point with VFB = 0 V.
5. Comparator gain is defined as: AV ∆V Output Compensation
∆V Current Sense Input
0.5
12
36
–
0
1.0
17
–
Unit
V
µA
dB
MHz
dB
mA
V
V/V
V
dB
µA
ns
V
V
ns
ns
V
V
%
mA
V
MOTOROLA ANALOG IC DEVICE DATA
3
3Pages UC3842A, 43A UC2842A, 43A
Figure 13. Output Saturation Voltage
versus Load Current
0
–1.0
VCC
TA = 25°C
Source Saturation
(Load to Ground)
VCC = 15 V
80 µs Pulsed Load
120 Hz Rate
–2.0
TA = –55°C
Figure 14. Output Waveform
VCC = 15 V
90% CL = 1.0 nF
TA = 25°C
3.0
TA = –55°C
2.0
TA = 25°C
1.0 Sink Saturation
(Load to VCC)
Gnd
0
0 200 400 600 800
IO, OUTPUT LOAD CURRENT (mA)
10%
50 ns/DIV
Figure 15. Output Cross Conduction
VCC = 30 V
CL = 15 pF
TA = 25°C
100 ns/DIV
Figure 16. Supply Current versus
Supply Voltatage
25
20
15
10 RT = 10 k
CT = 3.3 nF
VFB = 0 V
5 ISense = 0 V
TA = 25°C
0
0 10 20 30 40
VCC , SUPPLY VOLTAGE
6 MOTOROLA ANALOG IC DEVICE DATA
6 Page | |||
ページ | 合計 : 14 ページ | ||
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UC2842A | (UC2842A / UC2843A) HIGH PERFORMANCE CURRENT MODE CONTROLLERS | Motorola Semiconductors |
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