BRAKE (Pin 9) (Cont’d)

An internal pull-down resistor holds the input low when left

open. (Center- tapped motor configuration requires a power

supply disconnect transistor controlled by the BRAKE signal

- See Figure 2A).

ENABLE (Pin 10)

A high level at this input permits the output to sequence as

in Table 3, while a low disables all external output drivers.

An internal pull-up resistor holds the input high when left

open. Positive edges at this input will reset the overcurrent

flip-flop.

OVERCURRENT SENSE (Pin 12)

This input provides the user a way of protecting the motor

winding, drivers and power supply from an overload condi-

tion. The user provides a fractional-ohm resistor between

the negative supply and the common emitters of the NPN

drivers or common sources of N-Channel FET drivers. This

point is connected to one end of a potentiometer (e.g. 100K

ohms), the other end of which is connected to the positive

supply. The wiper pickoff is adjusted so that all outputs are

disabled for currents greater than the limit. The action of the

input is to disable all external output drivers. When BRAKE

exists, OVERCURRENT SENSE will be overridden. The

overcurrent circuitry latches the overcurrent condition. The

latch may be reset by the positive edge of either the saw-

tooth OSCILLATOR or the ENABLE input. When using the

ENABLE input as a chopped input, the OSC input should be

must be used to reset the overcurrent latch.

VTRIP (Pin 13)

This input is used in conjunction with the sawtooth OSC in-

put. When the voltage level applied to VTRIP is more neg-

ative than the waveform at the OSC input, the Outputs will

be enabled as shown in Table 3. When VTRIP is more pos-

itive than the sawtooth OSCILLATOR waveform the external

output drivers are disabled.

The sawtooth waveform at the OSC input typically varies

from .4 Vss to Vss-2V. The purpose of the VTRIP input in

conjunction with the OSCILLATOR is to provide variable

speed adjustment for the motor by means of PWM.

OSCILLATOR (Pin 14)

An R and C connected to this input (See Figure 6) provide

the timing components for a sawtooth OSCILLATOR. The

signal generated is used in conjunction with VTRIP to pro-

vide PWM for variable speed applications and to reset the

overcurrent condition.

OUTPUTS 1, 2, 3 (Pins 2, 3, 4)

For the LS7262, these open drain Outputs are enabled as

shown in Table 2 and provide base current to PNP tran-

sistors or gate drive to P-Channel FET drivers when COM-

MON is floating. If COMMON is held at Vss, these Outputs

can provide drive to NPN transistors or N-Channel FET

drivers. For the LS7260, these Outputs provide drive to

OUTPUTS 4, 5, 6 (Pins 6, 7, 8)

These open drain Outputs are enabled as in Table 2 and

provide base current to NPN transistors or gate drive to

N-Channel FET drivers.

COMMON (Pin 5)

The COMMON may be connected to Vss when using a

center-tapped motor configuration or when using all NPN

or N-Channel drivers. For the LS7260, the COMMON is

Vss (Pin 11)

Supply voltage positive terminal.

Supply voltage negative terminal (ground).

MAXIMUM RATINGS:

PARAMETER

SYMBOL

VALUE

UNIT

Storage Temperature

-65 to +150

°C

Operating Temperature

-25 to +85

°C

-40 to +125

°C

Voltage (any pin to Vss)

-30 to +.5

V

(1) Available on special order. Contact factory for details.

DC ELECTRICAL CHARACTERISTICS:

SYMBOL

MIN

TYP

MAX

UNIT

Supply Voltage

5

-

28

V

Supply Current (Outputs not loaded)

-

4.5

6

mA

7260-111297-2

Input Specifications:

BRAKE, ENABLE, CS1, CS2

-

150

-

K

Ω

S1, S2, S3, FWD/REV

Voltage (Logic "1")

-

V

(Logic "0")

0

-

V

OVERCURRENT SENSE (See Note)

Threshold Voltage

-

V