UNITRODE UC1625, UC2625, UC3625 Technical data

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5962-9168901MXA

application

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UC1625

UC2625

UC3625

Brushless DC Motor Controller

FEATURES

Drives Power MOSFETs or Power Darlingtons Directly

50V Open Collector High-Side Drivers

Latched Soft Start

High-speed Current-Sense Amplifier with Ideal Diode

Pulse-by-Pulse and Average Current Sensing

Over-Voltage and Under-Voltage Protection

Direction Latch for Safe Direction Reversal

Tachometer

Trimmed Reference Sources 30mA

Programmable Cross-Conduction Protection

Two-Quadrant and Four-Quadrant Operation

DESCRIPTION

The UC3625 family of motor controller ICs integrate most of the functions required for high-performance brushless DC motor control into one package. When coupled with external power MOSFETs or Darlingtons, these ICs perform fixed-frequency PWM motor control in either voltage or current mode while implementing closed loop speed control and braking with smart noise rejection, safe direction reversal, and cross–conduction protection.

Although specified for operation from power supplies between 10V and 18V, the UC1625 can control higher voltage power devices with external level-shifting components. The UC1625 contains fast, high-current push-pull drivers for low-side power devices and 50V open-collector outputs for high-side power devices or level shifting circuitry.

The UC1625 is characterized for operation over the military temperature range of –55°C to +125°C, while the UC2625 is characterized from –40°C to +105°C and the UC3625 is characterized from 0°C to 70°C. (NOTE: ESD Protection to 2kV)

TYPICAL APPLICATION

 

 

 

 

 

VREF

+5V TO HALL

 

 

 

+15V

 

VMOTOR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SENSORS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3kΩ

 

 

 

+

 

 

 

 

100nF

 

 

 

 

 

 

100nF

+

 

 

 

 

 

100µF

 

 

 

 

 

 

 

 

 

 

 

 

2N3904

 

 

 

 

 

 

20µF

 

 

 

 

 

20µF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10Ω

 

 

 

 

10kΩ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3kΩ

10kΩ

 

 

 

2

 

 

 

 

 

19

11

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

QUAD

ROSC

 

 

 

 

 

 

 

 

 

 

2N3906

 

 

33kΩ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

22

 

 

 

 

 

 

 

 

 

 

 

3kΩ

 

IRF9350

 

DIR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

 

 

 

 

 

 

 

6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1k

 

1

 

 

 

 

 

 

 

 

 

 

17

TO OTHER

 

 

 

MOTOR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

18

CHANNELS

 

 

 

 

 

 

100nF

28

 

 

 

 

 

UC3625

 

 

 

 

 

 

 

 

 

 

4kΩ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14

 

 

 

 

REQUIRED

 

 

 

27

 

 

 

 

 

 

 

 

 

 

TO OTHER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FOR BRAKE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CHANNELS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

13

 

 

 

AND FAST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

25

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REVERSE

 

 

2200pF

 

 

 

 

 

 

 

 

 

 

 

10Ω

IRF532

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12

 

 

 

 

 

COSC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BRAKE

 

 

21

26

3

24

23

8

9

10

4

5

7

10kΩ

 

 

 

 

 

 

 

3nF

68kΩ

 

 

 

 

 

 

 

 

 

 

100nF

 

 

 

 

 

 

 

 

5nF

 

100nF

 

 

 

 

 

240Ω

 

 

REQUIRED

 

 

 

CT

RT

 

 

 

 

FROM

 

 

 

 

FOR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HALL

 

 

 

 

 

0.02Ω

AVERAGE

 

 

 

 

 

 

 

 

 

2nF

 

SENSORS

5nF

240Ω

 

CURRENT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RS

SENSING

 

 

 

 

 

 

 

 

 

2nF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.02Ω

 

 

 

 

 

 

 

 

 

2nF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UDG-99045

SLUS353A - NOVEMBER 1999

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ABSOLUTE MAXIMUM RATINGS

VCC Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +20V

Pwr VCC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . +20V PWM In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 to 6V

E/A IN(+), E/A IN(–) . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 to 12V

ISENSE1, ISENSE2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . –1.3 to 6V OV–Coast, Dir, Speed-In, SSTART, Quad Sel . . . . . . –0.3 to 8V

H1, H2, H3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 to 12V PU Output Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 to 50V PU Output Current . . . . . . . . . . . . . . . . . . +200 mA continuous PD Output Current . . . . . . . . . . . . . . . . . . ±200 mA continuous E/A Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10 mA

ISENSE Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . –10 mA Tach Out Output Current . . . . . . . . . . . . . . . . . . . . . . . . ±10 mA

VREF Output Current . . . . . . . . . . . . . . . . . . –50 mA continuous Operating Temperature Range UC1625. . . . . . –55°C to 125°C

Operating Temperature Range UC2625. . . . . . –40°C to 105°C Operating Temperature Range UC3625. . . . . . . . . 0°C to 70°C

Note 1: Currents are positive into and negative out of the specified terminal.

Note 2: Consult Unitrode Integrated Circuits databook for information regarding thermal specifications and limitations of packages.

UC1625

UC2625

UC3625

CONNECTION DIAGRAM

DIL-28 (TOP VIEW)

J or N PACKAGE

Note 3: This pinout applies to the SOIC (DW), PLCC (Q), and LCC (L) packages (ie. pin 22 has the same function on all packages.)

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for: TA = 25°C; Pwr VCC = VCC = 12V; ROSC = 20k to VREF; COSC = 2nF; RTACH = 33k; CTACH = 10nF; and all outputs unloaded. TA = TJ.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Overall

 

 

 

 

 

Supply current

Over Operating Range

 

14.5

30.0

mA

VCC Turn-On Threshold

Over Operating Range

8.65

8.95

9.45

V

VCC Turn-Off Threshold

Over Operating Range

7.75

8.05

8.55

V

Overvoltage/Coast

 

 

 

 

 

OV-Coast Inhibit Threshold

Over Operating Range

1.65

1.75

1.85

V

OV-Coast Restart Threshold

 

1.55

1.65

1.75

V

OV-Coast Hysteresis

 

0.05

0.10

0.15

V

OV-Coast Input Current

 

–10

–1

0

A

Logic Inputs

 

 

 

 

 

H1, H2, H3 Low Threshold

Over Operating Range

0.8

1.0

1.2

V

H1, H2, H3 High Threshold

Over Operating Range

1.6

1.9

2.0

V

H1, H2, H3 Input Current

Over Operating Range, to 0V

-400

-250

–120

A

Quad Sel, Dir Thresholds

Over Operating Range

0.8

1.4

2.0

V

Quad Sel Hysteresis

 

 

70

 

mV

Dir Hysteresis

 

 

0.6

 

V

Quad Sel Input Current

 

–30

50

150

A

Dir Input Current

 

–30

–1

30

A

PWM Amp/Comparator

 

 

 

 

 

E/A In(+), E/A In(–) Input Current

To 2.5V

–5.0

–0.1

5.0

A

PWM In Input Current

To 2.5V

0

3

30

A

Error Amp Input Offset

0V < VCOMMON-MODE < 3V

–10

 

10

mV

Error Amp Voltage Gain

 

70

90

 

dB

2

UC1625

UC2625

UC3625

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for: TA = 25°C; Pwr VCC = VCC = 12V; ROSC = 20k to VREF; COSC = 2nF; RTACH = 33k; CTACH = 10nF; and all outputs unloaded. TA = TJ.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

PWM Amp/Comparator (cont.)

 

 

 

 

 

E/A Out Range

 

0.25

 

3.50

V

SSTART Pull-up Current

To 0V

–16

–10

–5

A

SSTART Discharge Current

To 2.5V

0.1

0.4

3.0

mA

SSTART Restart Threshold

 

0.1

0.2

0.3

V

Current Amp

 

 

 

 

 

Gain

ISENSE1 = .3V, ISENSE2 = .5V to .7V

1.75

1.95

2.15

V/V

 

 

 

 

 

 

Level Shift

ISENSE1 = .3V, ISENSE2 = .3V

2.4

2.5

2.65

V

Peak Current Threshold

ISENSE1 = 0V, Force ISENSE2

0.14

0.20

0.26

V

Over Current Threshold

ISENSE1 = 0V, Force ISENSE2

0.26

0.30

0.36

V

ISENSE1, ISENSE2 Input Current

To 0V

–850

–320

0

A

ISENSE1, ISENSE2 Offset Current

To 0V

 

±2

±12

A

Range ISENSE1, ISENSE2

 

–1

 

2

V

Tachometer/Brake

 

 

 

 

 

Tach-Out High Level

Over Operating Range, 10k to 2.5V

4.7

5

5.3

V

Tach-Out Low Level

Over Operating Range, 10k to 2.5V

 

 

0.2

V

On Time

 

170

220

280

s

On Time Change With Temp

Over Operating Range

 

0.1

 

%

RC-Brake Input Current

To 0V

–4.0

–1.9

 

mA

Threshold to Brake, RC-Brake

Over Operating Range

0.8

1.0

1.2

V

Brake Hysteresis, RC-Brake

 

 

0.09

 

V

Speed-In Threshold

Over Operating Range

220

257

290

mV

Speed-In Input Current

 

–30

–5

30

A

Low-Side Drivers

 

 

 

 

 

Voh, –1mA, Down From VCC

Over Operating Range

 

1.60

2.1

 

V Voh, –50mA, Down From VCC

Over Operating Range

 

1.75

2.2

V

Vol, 1mA

Over Operating Range

 

0.05

0.4

V

Vol, 50mA

Over Operating Range

 

0.36

0.8

V

Rise/Fall Time

10% to 90% Slew Time, into 1nF

 

50

 

ns

High-Side Drivers

 

 

 

 

 

Vol, 1mA

Over Operating Range

 

0.1

0.4

V

Vol, 50mA

Over Operating Range

 

1.0

1.8

V

Leakage Current

Output Voltage = 50V

 

 

25

A

Fall Time

10% to 90% Slew Time, 50mA Load

 

50

 

ns

Oscillator

 

 

 

 

 

Frequency

 

40

50

60

kHz

Frequency

Over Operating Range

35

 

65

kHz

Reference

 

 

 

 

 

Output Voltage

 

4.9

5.0

5.1

V

Output Voltage

Over Operating Range

4.7

5.0

5.3

V

Load Regulation

0mA to –20mA Load

–40

–5

 

mV

Line Regulation

10V to 18V VCC

–10

–1

10

mV

Short Circuit Current

Over Operating Range

50

100

150

mA

3

UNITRODE UC1625, UC2625, UC3625 Technical data

UC1625

UC2625

UC3625

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for: TA = 25°C; Pwr VCC = VCC = 12V; ROSC = 20k to VREF; COSC = 2nF; RTACH = 33k; CTACH = 10nF; and all outputs unloaded. TA = TJ.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Miscellaneous

 

 

 

 

 

Output Turn-On Delay

 

 

1

 

s

Output Turn-Off Delay

 

 

1

 

s

BLOCK DIAGRAM

Quad Sel

22

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5V

2

VREF

RC-Osc

25

OSC

 

 

 

S

Q

 

 

REFERENCE

 

PWM CLOCK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PWM In

26

 

 

 

 

R

 

 

 

 

 

 

E/A Out

27

 

 

 

 

 

 

 

 

 

 

 

E/A In(+)

1

 

 

2.9V

 

 

 

 

 

 

 

 

E/A In (–)

28

 

 

 

 

 

 

 

 

10µA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SSTART

24

 

 

 

 

 

 

 

 

 

 

 

ISENSE

3

ABS VALUE

 

 

0.2V

 

 

R

Q

Q1

 

 

 

 

 

250Ω

 

 

 

 

 

 

 

ISENSE1

4

2.5V

 

 

 

 

S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2X

 

 

 

 

 

 

 

 

 

 

 

ISENSE2

5

 

 

3.1V

 

 

 

 

 

 

 

 

VCC

19

 

 

 

 

 

 

 

 

 

 

 

 

9V

 

 

 

 

 

 

 

PWM

 

 

OV-Coast

23

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CLOCK

 

 

 

1.75V

 

 

 

 

 

 

 

 

 

18

PUA

 

 

 

 

 

 

 

 

 

 

 

 

Dir

6

 

 

 

 

 

 

 

 

 

17

PUB

 

 

DIRECTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Speed-In

7

LATCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.25V

 

 

 

 

 

 

 

 

 

16

PUC

 

 

 

 

 

 

 

 

 

 

 

 

 

+5V

PWM CLOCK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DIR

COAST

CHOP

QUAD

 

 

11

Pwr Vcc

H1

8

 

D

Q

H1

 

 

 

 

CROSS

14

PDA

 

 

 

 

 

 

 

 

 

 

CONDUCTION

 

 

 

 

 

 

 

 

 

 

 

 

 

+5V

 

L

 

 

 

 

 

 

PROTECTION

 

 

 

 

 

 

 

 

 

 

LATCHES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H2

9

 

D

Q

H2

DECODER

 

 

 

 

 

 

+5V

 

L

 

 

 

 

 

 

 

13

PDB

 

 

 

 

 

 

 

 

 

 

 

H3

9

 

D

Q

H3

 

 

 

 

 

 

 

 

 

 

L

 

 

BRAKE

 

 

 

12

PDC

 

 

EDGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DETECT

 

 

 

 

 

 

 

 

15

GND

 

 

 

 

 

 

 

 

 

 

+5V

 

 

 

 

 

 

 

 

 

 

 

 

 

2k

 

 

 

 

 

 

 

 

 

 

RC-Brake

21

ONE

 

 

 

 

 

 

 

 

20

Tach-Out

 

 

SHOT

 

 

 

 

 

 

 

 

 

 

 

1V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UDG-99044

 

 

 

 

 

 

4

 

 

 

 

 

 

PIN DESCRIPTIONS

Dir, Speed-In: The position decoder logic translates the Hall signals and the Dir signal to the correct driver signals (PUs and PDs). To prevent output stage damage, the signal on Dir is first loaded into a direction latch, then shifted through a two-bit register.

As long as Speed-In is less than 250mV, the direction latch is transparent. When Speed-In is higher than 250mV, the direction latch inhibits all changes in direction. Speed-In can be connected to Tach-Out through a filter, so that the direction latch is only transparent when the motor is spinning slowly, and has too little stored energy to damage power devices.

Additional circuitry detects when the input and output of the direction latch are different, or when the input and output of the shift register are different, and inhibits all output drives during that time. This can be used to allow the motor to coast to a safe speed before reversing.

The shift register guarantees that direction can't be changed instantaneously. The register is clocked by the PWM oscillator, so the delay between direction changes is always going to be between one and two oscillator periods. At 40kHz, this corresponds to a delay of between 25µs and 50µs. Regardless of output stage, 25µs dead time should be adequate to guarantee no overlap cross-conduction. Toggling DIR will cause an output pulse on Tach-Out regardless of motor speed.

E/A In(+), E/A In(–), E/A Out, PWM In: E/A In(+) and E/A In(–) are not internally committed to allow for a wide

variety of uses. They can be connected to the ISENSE, to Tach-Out through a filter, to an external command volt-

age, to a D/A converter for computer control, or to another op amp for more elegant feedback loops. The error amplifier is compensated for unity gain stability, so E/A Out can be tied to E/A In(–) for feedback and major loop compensation.

E/A Out and PWM In drive the PWM comparator. For voltage-mode PWM systems, PWM In can be connected to RC-Osc. The PWM comparator clears the PWM latch, commanding the outputs to chop.

The error amplifier can be biased off by connecting E/A In(–) to a higher voltage than E/A In(+). When biased off, E/A Out will appear to the application as a resistor to ground. E/A Out can then be driven by an external amplifier.

GND: All thresholds and outputs are referred to the GND pin except for the PD and PU outputs.

UC1625

UC2625

UC3625

H1, H2, H3: The three shaft-position sensor inputs consist of hysteresis comparators with input pull-up resistors. Logic thresholds meet TTL specifications and can be driven by 5V CMOS, 12V CMOS, NMOS, or open-collectors.

Connect these inputs to motor shaft position sensors that are positioned 120 electrical degrees apart. If noisy signals are expected, zener clamp and filter these inputs with 6V zeners and an RC filter. Suggested filtering components are 1kΩ and 2nF. Edge skew in the filter is not a problem, because sensors normally generate modified Gray code with only one output changing at a time, but rise and fall times must be shorter than 20µs for correct tachometer operation.

Motors with 60 electrical degree position sensor coding can be used if one or two of the position sensor signals is inverted.

ISENSE1, ISENSE2, ISENSE: The current sense amplifier has a fixed gain of approximately two. It also has a

built-in level shift of approximately 2.5V. The signal appearing on ISENSE is:

ISENSE = 2.5V + (2 ABS(ISENSE1 ISENSE 2 ))

ISENSE1 and ISENSE2 are interchangeable and can be used as differential inputs. The differential signal applied

can be as high as ±0.5V before saturation.

If spikes are expected on ISENSE1 or ISENSE2, they are best filtered by a capacitor from ISENSE to ground. Filtering this way allows fast signal inversions to be cor-

rectly processed by the absolute value circuit. The peak-current comparator allows the PWM to enter a cur- rent-limit mode with current in the windings never exceeding approximately 0.2V/RSENSE. The over current comparator provides a fail-safe shutdown in the unlikely

case of current exceeding 0.3V/RSENSE. Then, soft start is commanded, and all outputs are turned off until the

high current condition is removed. It is often essential to

use some filter driving ISENSE1 and ISENSE2 to reject extreme spikes and to control slew rate. Reasonable start-

ing values for filter components might be 250Ω series

resistors and a 5nF capacitor between ISENSE1 and ISENSE2. Input resistors should be kept small and matched to maintain gain accuracy.

OV-Coast: This input can be used as an over-voltage shutdown in put, as a coast input, or both. This input can be driven by TTL, 5V CMOS, or 12V CMOS.

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