UC2638
UC1638
UC2638
UC3638
Advanced PWM Motor Controller
FEATURES
∙Single or Dual Supply Operation
∙Accurate High Speed Oscillator
∙Differential X5 Current Sense Amplifier
∙Bidirectional Pulse-by-Pulse Current Limiting
∙Programmable Oscillator Amplitude and PWM Deadband
∙Dual 500mA Totem Pole Output Drivers
∙Dual 60V, 50mA Open Collector Drivers
∙Undervoltage Lockout
DESCRIPTION
The UC1638 family of integrated circuits are advanced pulse width modulators intended for a variety of PWM motor drive and amplifier applications requiring either uni-directional or bi-directional drive circuits. Similar in architecture to the UC1637, all necessary circuitry is included to generate an analog error signal and modulate two bi-directional pulse train outputs in proportion to the error signal magnitude and polarity.
Key features of the UC1638 include a programmable high speed triangle oscillator, a 5X differential current sensing amplifier, a high slew rate error amplifier, high speed PWM comparators, and two 50mA open collector as well as two ±500mA totem pole output stages. The individual circuit blocks are designed to provide practical operation to switching frequencies of 500kHz.
Significant improvements in circuit speed, elimination of many external programming components, and the inclusion of a differential current sense amplifier, allow this controller to be specified for higher performance applications, yet maintain the flexibility of the UC1637. The current sense amplifier in conjunction with the error amplifier can be configured for average current feedback. The additional open collector outputs provide a drive signal
continued
BLOCK DIAGRAM
UDG-95048-4 |
1/98 |
DESCRIPTION (cont.)
for the highside switches in a full bridge configuration. The programmable AREFIN pin allows for single or dual supply operation. Oscillator ramp amplitude and PWM deadband are programmable by tapping a voltage divider off the 5V reference to the appropriate programming input (PVSET or DB).
Additional features include a precision externally available 5V reference, undervoltage lockout, pulse-by-pulse peak current limiting, and a remote shutdown port. The UC1638 family is available in the 20 pin N, DW and J packages. Consult the factory for other packaging options.
CONNECTION DIAGRAMS
DIL-20 (Top View)
N or J Package
UC1638
UC2638
UC3638
ABSOLUTE MAXIMUM RATINGS
Supply Voltage VCC (referenced to VEE) . . . . . . . . . . . . . 40V Output Drivers (AOUT2, BOUT2)
Currents (continuous) . . . . . . . . . . . . . . . . . . . . . . . . ±0.25A Currents (peak) . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±500mA REF Output Current . . . . . . . . . . . . . . . . . . . . Internally Limited PVSET, DB, RT, INV, REF, CSOUT . . . . . . . . . . . . . 0.3 to 10V CS+, CS- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VEE–1V to VCC CT, AREF, AREFIN, COMP, SD . . . . . . . . . . . . . . . . VEE − 0.3 Output Voltage (AOUT1, BOUT1) . . . . . . . . . . . . . . . . . . . . 60V Storage temperature. . . . . . . . . . . . . . . . . . . . −65°C to +150°C Junction Temperature . . . . . . . . . . . . . . . . . . . −55°C to +150°C Lead temperature (soldering, 10 sec.) . . . . . . . . . . . . . . +300°C
Currents are positive into, negative out of the specified terminal. Consult packaging section of data book for thermal limitation considerations of packages.
SOIC-20 (Top View) |
DW Package |
PLCC-20 (Top View)
Q Package
2
UC1638
UC2638
UC3638
ELECTRICAL CHARACTERISTICS |
Unless otherwise specified; VCC = 15V, VEE =–15V, CT = 680pF, RT = 3k, |
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VPVSET = 1.5V, VCOMP = 0V, VCSOUT = 0V, VDB = REF, VEXTREF = 0V, VSD = |
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VCC – 3V, TA = −55°C to 125°C for the UC1638, −25°C to 85°C for the UC2638, |
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0°C to 70°C for the UC3638. T A = TJ. |
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PARAMETER |
TEST CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
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Overall |
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Supply Current, Operating |
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|
15 |
23 |
mA |
|
UVLO Threshold |
Reference to VEE |
|
9 |
10 |
V |
|
UVLO Hysteresis |
Reference to VEE |
|
1 |
|
V |
|
Voltage Amplifier |
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Input Offset Voltage |
COMP = 0V |
−15 |
0 |
15 |
mV |
|
VSENSE Bias Current |
|
0 |
0.5 |
2 |
mA |
|
Open Loop Gain |
COMP = −5V to +5V |
75 |
100 |
|
dB |
|
CMRR |
VCM = −5V to +5V |
70 |
100 |
|
dB |
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PSRR |
VCM = 0V, VCC − VEE = 10V to 36V |
70 |
90 |
|
dB |
|
VOUT High |
INV = −0.1V, RL = 10k |
13 |
13.6 |
|
V |
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VOUT Low |
INV = +0.1V, RL = 10k |
|
−13.8 |
–13 |
V |
|
Slew Rate Rising and Falling |
Overdrive = ±1V |
|
12 |
|
V/μs |
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Output Source Current |
COMP Shorted to VEE |
5 |
15 |
|
mA |
|
Output Sink Current |
COMP Shorted to VCC |
15 |
40 |
|
mA |
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Gain Bandwidth Product |
FIN = 100kHz, 10mV p-p |
1 |
5 |
|
MHz |
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5V Reference |
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Output Voltage |
IREF = −1mA, TA = 25°C |
4.925 |
5 |
5.075 |
V |
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Output Voltage |
IREF = −1mA |
4.875 |
5 |
5.125 |
V |
|
Load Regulation |
IREF = −1mA to −10mA |
−15 |
2 |
15 |
mV |
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Line Regulation |
VCC - VEE = 10V to 36V |
−15 |
2 |
15 |
mV |
|
Short Circuit Current |
VREF = 0V |
15 |
70 |
|
mA |
|
Oscillator |
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Initial Accuracy |
TA = 0°C – 70°C |
86 |
98 |
110 |
kHz |
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Voltage Stability |
VCC − VEE = 10V to 36V |
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2 |
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% |
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Total Variation |
Line, Temperature |
76 |
98 |
120 |
kHz |
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PVSET Input Bias Current |
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0.5 |
3 |
μA |
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PVSET Input Voltage Range |
(Note 1) |
0.5 |
|
VREF |
V |
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Amplitude Limit |
(Note 1) |
VEE+3 |
|
VCC−3 |
V |
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AOUT1, BOUT1 Output Drivers |
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Output Low Voltage |
IOUT = 1mA, Ref. to PVE, PVE = 0V |
|
0.9 |
1.3 |
V |
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IOUT = 50mA |
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1.2 |
1.8 |
V |
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Leakage Current |
Output Voltage = 50V |
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0.1 |
50 |
μA |
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AOUT2, BOUT2 Output Drivers |
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Output High Voltage |
IOUT = −20mA, Ref. to PVE, PVE = 0V |
12.2 |
13.5 |
|
V |
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IOUT = −100mA, Ref. to PVE, PVE = 0V |
12 |
13.5 |
|
V |
|
Output High Clamp Level |
IOUT = −20mA, Ref. to PVE, PVE = VEE |
|
14.4 |
16.5 |
V |
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Output Low Voltage |
IOUT = 20mA, Ref. to PVE, PVE = 0V |
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0.4 |
1 |
V |
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IOUT = 100mA, Ref. to PVE, PVE = 0V |
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0.6 |
2.2 |
V |
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Output Rise Time |
COUT = 1nF |
|
50 |
100 |
ns |
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Output Fall Time |
COUT = 1nF |
|
50 |
100 |
ns |
3