UNITRODE UC1620, UC2620 Technical data

查询UC1620供应商

Switchmode Driver for 3-∅ Brushless DC Motors

UC1620
UC3620

FEATURES

• 2A Continuous, 3A Peak Output
Current

• 8V to 40V Operation

• Internal High Gain Amplifier for

Velocity Control Applications

• TTL Compatible Hall Inputs

• Mask Programmable Decode Logic

• Pulse-by-Pulse Current Limiting

• Internal Thermal Shutdown Protection

• Under-Voltage Lockout

• Available in SP Hermetic Package

BLOCK DIAGRAM

DESCRIPTION

The UC3620 is a br ushless DC motor driver capable of decoding and
driving al l 3 windings of a 3-phase br ushles s DC motor. In addition, an
on-board c urrent comp arator, oscillator, and high gain Op-Amp provide
all necessar y circuitr y for implementing a high performance, chopped
mode servo amplifier. Full protection, including thermal shutdown,
pulse-by-pulse current limiting, and under-voltage lockout aid in the
simple implementation of reliable designs. Both conducted and radiated
EMI have been grea tly redu ced by limi ting the output dv/dt to 150V /µs
for any load condition.

The UC1620SP is characterized for operation over the full military tem­perature range of -55°C to +125°C, while the UC3620SP is charac­terized for 0°C to +70°C.

3/97

1

UC1620
UC3620

ABSOLUTE MAXIMUM RATINGS

(Note 1)

Supply Voltage, VCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V

Output Current, Source or Sink

CONNECTION DIAGRAMS

SP Hermetic Power DIL

Non-Repetitive (t = 100µsec), lo . . . . . . . . . . . . . . . . . . . . 3A

Repetitive (80% on - 20% off; tON = 10ms) . . . . . . . . . . 2.5A

DC Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2A

Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +Vcc

Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +Vcc

Total Power Dissipation (at T

CASE

= 75° C)

for SP Package (Note 2). . . . . . . . . . . . . . . . . . . . . . . . . . 15W

Storage Temperature . . . . . . . . . . . . . . . . . . . . -65°C to +150°C

Operating Junction Temperature . . . . . . . . . . . -55°C to +150°C

Note 1: All voltages are with respect to g round. Currents are

positive into, negative out of the specified terminal.

Note 2: Consult Packaging Section of Databook for thermal

limitations and considerations of package.

ELECTRICAL CHARACTERISTICS:

Unless otherwise stated, these spec ifications apply for TA = 0°C to 70°C for 3620; T
= 55°C to +125°C for UC1620; VCC = 20V, RT = 20V, RT = 10k, C

-2.2nF. TA=T

T =

PARAMETER TEST CONDITIONS UC3620 UC1 620 UNIT

MIN TYP MAX MIN TYP MAX

Error Amplifier Section

Input Offset Voltage 1.5 10 1.5 10 mV
Input Bias Current -.25 -2.0 -.25 -2.0 µA
Input Offset Current 15 250 15 250 nA
Common Mode Range Vcc = 8V to 40V 0 V
Open Loop Gain ∆V
Unity Gain Bandwidth T
Output Sink Current V
Output Source Current V

= 1V to 4V 80 100 75 100 dB

COMP

= 25°C, Note 2 0.8 0.8 MHz

J

= 1V 2 2 mA

COMP

= 4V 8 8 mA

COMP

-2 0 VIN-2 V

IN

Current Sense Section

Input Bias Current -2.0 -5 -2.0 -5 µA
Internal Clamp .425 0.5 .575 .405 0.5 .595 V
Divider Gain .180 0.2 .220 .170 0.2 .230 V/V
Internal Offset Voltage .8 1.0 1.2 .75 1.0 1.25 V

Timing Section

Output Off Tim e 18 20 22 17 20 23 µs
Upper Mono Threshold 5.0 5.0 V
Lower Mono Threshold 2.0 2.0 V

Decoder Section

High-Level Input Voltage 2.2 2.5 V
Low-Level Inpu t Vol ta ge 0.8 0.8 V
High-Level Input Current 10 10 µA
Low-Level Input Curre nt -10 -10 µA

Output Section

Output Leakage Curre nt V
VF1 Schottky Diode I
VF1 Substrat e Diode I
Total Output Voltage Drop I

= 40V 500 1500 µ A

CC

= 2A 1.5 2.0 1.5 2.0 V

O

= 2A 2.2 3.0 2.2 3.0 V

O

= 2A, Note 3 3.0 3.6 3.0 3.6 V

O

A

J.

2

UC1620
UC3620

ELECTRICAL CHARACTERISTICS:

PARAMETER TEST CONDITIONS UC3620 UC1 620 UNIT

Output Section (cont.)

Output Rise Time R
Output Fall Time R

Under Voltage Lock ou t

Startup Threshold 8.0 8.0 V
Threshold Hysteresis 0.5 0.5 V

Thermal Shutdown

Junction Temperature Note 2 150 180 150 180 °C

Total Standby Current

Supply Current 32 55 32 55 mA

Note 2: These paramete rs , al th ou gh gu aranteed over the recommend ed op erating conditi on s , ar e no t 10 0% tes te d in prod uc ti on .
Note 3: The total voltage drop is defined as the sum of both top and bottom side driver.

TABLE 1

STEP FWD/

REV

1 1 101 H L O
2 1 100 H O L
3 1 110 O H L
4 1 010 L H O
5 1 011 L O H
6 1 001 O L H
1 0 101 L H O
2 0 100 L O H
3 0 110 O L H
4 0 010 H L O
5 0 011 H O L
6 0 001 O H L

H = HIGH OUTPUT
L = LOW OUTPUT
O = OPEN OUTPUT

Ha Hb Hc A

OUT

Unless otherwise stated, these spec ifications apply for T
= 55°C to +125°C for UC1620; VCC = 20V, RT = 20V, RT = 10k, C

MIN TYP MAX MIN TYP MAX

= 44Ω 150 150 ns

L

= 44Ω 150 150 ns

L

Hall lines require pull-up resistors.

B

OUT

C

OUT

CURRENT SENSING

Referring to Figure 1, emitter current is sensed across R
and fed back through a low pass filter to the current
sense pin 7. This filter is required to eliminate false trig­gering of the monostable due to leading edge current
spikes. Actual filter values, although somewhat depend­ent on external loads, will generally be in the 1kΩ and
1000pF range.

TIMING

An R-C time constant on pin 9 is used by the monostable
to generate a fixed off time at the outputs according to the
formula:

T

OFF

=

As the peak current in the emitters approaches the value
at the minus (-) input of the on-board comparator, the

= 0°C to 70°C for 3620; T

A

T =

.916RTC

T

-2.2nF. TA=T

monostable is tr i gg er e d, c au s in g t he outputs to be tur ned

A

J.

S

CIRCUIT DESCRIPTION

The UC3620 is designed for implementation of a com­plete 3-∅ brushless DC servo drive using a minimum
number of external components. Below is a functional de­scription of each major circuit feature.

DECODER

Table 1 shows the dec oding sc heme used in the UC3620
to decode and drive each of three high current totem pole
output sta ge s. A forward/reverse signal, pin 13, is used to
provide direc tion. At any point in time, one driver is sour­cing, one dr iver is sin king, an d the rem aining driver is off
or tri-s tated. Pulse width modulation is acc omplished by
turning the sink driver off during the monostable reset
time, producing a fixed off-time chop mode. Controlled
output rise and fall times help reduce electrical switching
noise while maintaining re latively small switching loss es.

Figure 1.

3

Current Sense Filter