MODE CONTROLLERS. UC3843B Datasheet

UC3843B CONTROLLERS. Datasheet pdf. Equivalent

UC3843B Datasheet
Recommendation UC3843B Datasheet
Part UC3843B
Description (UC3842B / UC3843B) HIGH PERFORMANCE CURRENT MODE CONTROLLERS
Feature UC3843B; www.DataSheet4U.com Order this document by UC3842B/D UC3842B, 43B UC2842B, 43B High Performance Cu.
Manufacture Motorola
Datasheet
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Motorola UC3843B
www.DataSheet4U.com
Order this document by UC3842B/D
UC3842B, 43B
UC2842B, 43B
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–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 and surface mount
(SO–8) 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 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).
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
Simplified Block Diagram
VCC 7(12)
Vref
8(14) R
5.0V
Reference
R
Vref
Undervoltage
Lockout
RT/CT
Oscillator
4(7)
Voltage
Feedback
+
Input
2(3) Error
Output
Amplifier
Compensation
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Gnd 5(9)
Latching
PWM
VCC
Undervoltage
Lockout
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
HIGH PERFORMANCE
CURRENT MODE
CONTROLLERS
N SUFFIX
PLASTIC PACKAGE
CASE 626
D1 SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
8
1
8
1
D SUFFIX
PLASTIC PACKAGE
CASE 751A
(SO–14)
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
UC384XBD
SO–14
UC384XBD1
UC384XBN
TA = 0° to +70°C
SO–8
Plastic
UC284XBD
SO–14
UC284XBD1 TA = – 25° to +85°C
UC284XBN
SO–8
Plastic
UC384XBVD
SO–14
UC384XBVD1 TA = – 40° to +105°C
UC384XBVN
SO–8
Plastic
X indicates either a 2 or 3 to define specific device part
numbers.
MOTOROLA ANALOG IC DEVICE DATA
© Motorola, Inc. 1996
Rev 1
1



Motorola UC3843B
www.DataSheet4U.com
UC3842B, 43B UC2842B, 43B
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Total Power Supply and Zener Current
Output Current, Source or Sink (Note 1)
Output Energy (Capacitive Load per Cycle)
Current Sense and Voltage Feedback Inputs
Error Amp Output Sink Current
Power Dissipation and Thermal Characteristics
D Suffix, Plastic Package, SO–14 Case 751A
Maximum Power Dissipation @ TA = 25°C
Thermal Resistance, Junction–to–Air
D1 Suffix, Plastic Package, SO–8 Case 751
Maximum Power Dissipation @ TA = 25°C
Thermal Resistance, Junction–to–Air
N Suffix, Plastic Package, Case 626
Maximum Power Dissipation @ TA = 25°C
Thermal Resistance, Junction–to–Air
Operating Junction Temperature
Operating Ambient Temperature
UC3842B, UC3843B
UC2842B, UC2843B
UC3842BV, UC3843BV
Storage Temperature Range
(ICC + IZ)
IO
W
Vin
IO
30
1.0
5.0
– 0.3 to + 5.5
10
mA
A
µJ
V
mA
PD
RθJA
PD
RθJA
PD
RθJA
TJ
TA
Tstg
862 mW
145 °C/W
702 mW
178 °C/W
1.25
100
+150
0 to + 70
– 25 to + 85
–40 to +105
– 65 to +150
W
°C/W
°C
°C
°C
ELECTRICAL CHARACTERISTICS (VCC = 15 V [Note 2], 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 3], unless otherwise noted.)
UC284XB
UC384XB, XBV
Characteristics
Symbol Min Typ Max Min Typ Max Unit
REFERENCE SECTION
Reference Output Voltage (IO = 1.0 mA, TJ = 25°C)
Vref
4.95 5.0 5.05 4.9
5.0
Line Regulation (VCC = 12 V to 25 V)
Regline
2.0 20
2.0
Load Regulation (IO = 1.0 mA to 20 mA)
Regload
3.0 25
3.0
Temperature Stability
TS
– 0.2 –
– 0.2
Total Output Variation over Line, Load, and Temperature
Output Noise Voltage (f = 10 Hz to 10 kHz, TJ = 25°C)
Vref
Vn
4.9
5.1 4.82
– 50 –
– 50
Long Term Stability (TA = 125°C for 1000 Hours)
S
– 5.0 –
– 5.0
Output Short Circuit Current
ISC – 30 – 85 –180 – 30 – 85
OSCILLATOR SECTION
Frequency
TJ = 25°C
TA = Tlow to Thigh
TJ = 25°C (RT = 6.2 k, CT = 1.0 nF)
fOSC
49 52 55 49 52
48 – 56 48 –
225 250 275 225 250
Frequency Change with Voltage (VCC = 12 V to 25 V) fOSC/V
0.2 1.0
0.2
Frequency Change with Temperature
TA = Tlow to Thigh
fOSC/T
1.0
– 0.5
Oscillator Voltage Swing (Peak–to–Peak)
VOSC – 1.6 –
– 1.6
Discharge Current (VOSC = 2.0 V)
TJ = 25°C
TA = Tlow to Thigh (UC284XB, UC384XB)
TA = Tlow to Thigh (UC384XBV)
Idischg
7.8 8.3 8.8 7.8 8.3
7.5 – 8.8 7.6 –
– – – 7.2 –
NOTES: 1. Maximum Package power dissipation limits must be observed.
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 = 0°C for UC3842B, UC3843B
www.DataSheet4U.comTlow = –25°C for UC2842B, UC2843B
Tlow = –40°C for UC3842BV, UC3843BV
Thigh = +70°C for UC3842B, UC3843B
Thigh = +85°C for UC2842B, UC2843B
Thigh = +105°C for UC3842BV, UC3843BV
5.1
20
25
5.18
–180
V
mV
mV
mV/°C
V
µV
mV
mA
kHz
55
56
275
1.0 %
–%
–V
mA
8.8
8.8
8.8
2 MOTOROLA ANALOG IC DEVICE DATA



Motorola UC3843B
www.DataSheet4U.com
UC3842B, 43B UC2842B, 43B
ELECTRICAL CHARACTERISTICS (VCC = 15 V [Note 2], 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 3], unless otherwise noted.)
UC284XB
UC384XB, XBV
Characteristics
Symbol Min Typ Max Min Typ Max Unit
ERROR AMPLIFIER SECTION
Voltage Feedback Input (VO = 2.5 V)
Input Bias Current (VFB = 5.0 V)
Open Loop Voltage Gain (VO = 2.0 V to 4.0 V)
Unity Gain Bandwidth (TJ = 25°C)
Power Supply Rejection Ratio (VCC = 12 V to 25 V)
Output Current
Sink (VO = 1.1 V, VFB = 2.7 V)
Source (VO = 5.0 V, VFB = 2.3 V)
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)
(UC284XB, UC384XB)
(UC384XBV)
VFB
IIB
AVOL
BW
PSRR
ISink
ISource
VOH
VOL
2.45 2.5 2.55 2.42 2.5 2.58
V
– 0.1 –1.0
– 0.1 – 2.0
µA
65 90 – 65 90 – dB
0.7 1.0 – 0.7 1.0 – MHz
60 70 – 60 70 – dB
2.0 12 – 2.0 12 –
– 0.5 –1.0 – – 0.5 –1.0 –
mA
5.0 6.2 – 5.0 6.2 –
V
– 0.8 1.1 – 0.8 1.1
– – – – 0.8 1.2
CURRENT SENSE SECTION
Current Sense Input Voltage Gain (Notes 4 & 5)
(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 4)
(UC284XB, UC384XB)
(UC384XBV)
Vth V
0.9 1.0 1.1 0.9 1.0 1.1
– – – 0.85 1.0 1.1
Power Supply Rejection Ratio
VCC = 12 V 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)
(ISink = 200 mA) (UC284XB, UC384XB)
(UC384XBV)
High State (ISource = 20 mA) (UC284XB, UC384XB)
(UC384XBV)
(ISource = 200 mA)
VOL
VOH
– 0.1 0.4 – 0.1 0.4
– 1.6 2.2 – 1.6 2.2
– – – – 1.6 2.3
13 13.5
13 13.5
– – – 12.9 13.5 –
12 13.4
12 13.4
Output Voltage with UVLO Activated
VCC = 6.0 V, ISink = 1.0 mA
VOL(UVLO) – 0.1 1.1 – 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 (VCC)
UCX842B, BV
UCX843B, BV
Vth
15 16 17 14.5 16 17.5
7.8 8.4 9.0 7.8 8.4 9.0
dB
µA
ns
V
V
ns
ns
V
Minimum Operating Voltage After Turn–On (VCC)
UCX842B, BV
UCX843B, BV
VCC(min)
V
9.0 10 11 8.5 10 11.5
7.0 7.6 8.2 7.0 7.6 8.2
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 = 0°C for UC3842B, UC3843B
Thigh = +70°C for UC3842B, UC3843B
Tlow = –25°C for UC2842B, UC2843B
Thigh = +85°C for UC2842B, UC2843B
www.DataSheet4U.comTlow = –40°C for UC3842BV, UC3843BV
Thigh = +105°C for UC3842BV, UC3843BV
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
MOTOROLA ANALOG IC DEVICE DATA
3







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