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FEATURES

· DELIVERS UP TO 5A CONTINUOUS OUTPUT

· OPERATES AT SUPPLY VOLTAGES UP TO 60V

· TTL AND CMOS COMPATIBLE INPUTS

· NO "SHOOT-THROUGH" CURRENT

· THERMAL SHUTDOWN (OUTPUTS OFF) AT 160°C

· SHORTED LOAD PROTECTION (to VS or PGND or

SHORTED LOAD)

· NO BOOTSTRAP CAPACITORS REQUIRED

· PROGRAMMABLE ONBOARD PWM

APPLICATIONS

· DC MOTOR DRIVES

· POSITION AND VELOCITY SERVOMECHANISMS

· FACTORY AUTOMATION ROBOTS

· NUMERICALLY CONTROLLED MACHINERY

· COMPUTER PRINTERS AND PLOTTERS

· AUDIO AMPLIFICATION

FIGURE 1. BLOCK DIAGRAM

DESCRIPTION

The SA56 is a 5A PWM Amplifier designed for motion con-

trol applications. The device is built using a multi-technology
process which combines bipolar and CMOS control circuitry
with DMOS power devices in the same monolithic structure.
Ideal for driving DC and stepper motors; the SA56 accom-
modates peak output currents up to 10A. An innovative circuit
which facilitates low-loss sensing of the output current has
been implemented. On board PWM oscillator and comparator
are used to convert an analog signal into PWM direction and
magnitude for motor control applications, or to amplify audio
signals using class D amplification.

23 PIN SIP

PACkAGE STYLE EX

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ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

SA56

ABSOLUTE MAXIMUM RATINGS

SUPPLY VOLTAGE, V

5.5V

SUPPLY VOLTAGE, V

60V

PEAK OUTPUT CURRENT (100mS)

10A

CONTINUOUS OUTPUT CURRENT

POWER DISSIPATION

TBD

POWER DISSIPATION (T

= 25°C, Free Air)

JUNCTION TEMPERATURE, T

J(MAX)

150°C

ESD SUSCEPTIBILITY (Logic Signals Only)

1500V

STORAGE TEMPERATURE, T

STG

40°C to +150°C

LEAD TEMPERATURE (Soldering, 10 sec.)

300°C

JUNCTION TEMPERATURE, T

40°C to +150°C

NOTE: These specifications apply for V

= 50V and V

= 5V at 25

C, unless otherwise specified.

SPECIFICATIONS

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

VDD

4.5

5.5

SWITCH ON RESISTANCE, R

(ON)

Output Current = 5A

0.25

0.6

N-Channel

SWITCH ON RESISTANCE, R

(ON)

Output Current = 5A

0.3

0.6

P-Channel

CLAMP DIODE FORWARD DROP, V

CLAMP

Clamp Current = 5A

1.43

TBD

LOGIC LOW INPUT VOLTAGE, V

-0.5

0.8

LOGIC LOW INPUT CURRENT, I

= 0.1V

-10

+10

µA

LOGIC HIGH INPUT VOLTAGE, V

LOGIC HIGH INPUT CURRENT, I

= 5.5V

-10

µA

CURRENT SENSE OUTPUT

OUT

= 1A

300

350

µA

OUT

= 5A

1.3

1.5

CURRENT SENSE LINEARITY

1A I

OUT

±1

±5

100 mA I

OUT

±8

5A I

OUT

10A (Peak Currents only)

±8

SHUTDOWN TEMPERATURE, T

JSD

Outputs Turn OFF

160

°C

QUIESCENT SUPPLY CURRENT, I

No Load, F

= 23KHz 50% DUC

TBD

QUIESCENT SUPPLY CURRENT, I

No Load, F

= 23KHz 50% DUC

OUTPUT TURN-ON DELAY TIME, t

Don

Sourcing Outputs, I

OUT

= 1A

Sinking Outputs, I

OUT

= 1A

OUTPUT TURN-ON SWITCHING TIME, t

Sourcing Outputs, I

OUT

= 1A

Sinking Outputs, I

OUT

= 1A

OUTPUT TURN-OFF DELAY TIMES, t

Doff

Sourcing Outputs, I

OUT

= 1A

Sinking Outputs, I

OUT

= 1A

OUTPUT TURN-OFF SWITCHING TIME, t

off

Sourcing Outputs, I

OUT

= 1A

Sinking Outputs, I

OUT

= 1A

MINIMUM INPUT PULSE WIDTH, t

100

(DIGITAL MODE)

PWM FREQUENCY (DIGITAL MODE)

500

KHz

REFERENCE VOLTAGE

2.4

2.5

2.6

Vref OUTPUT CURRENT (Vref 2.5V)

Source Only, No current sink capability

ANALOG INPUT RANGE FOR

Load Current = 400µA

FULL MODULATION
HIGH CURRENT SHUTDOWN RESPONSE Output shorted

250

800

(No bypass capacitor at SCin pin)

APEX MICROTECHNOLOGY CORPORATION · TELEPHONE (520) 690-8600 · FAX (520) 888-3329 · ORDERS (520) 690-8601 · EMAIL prodlit@apexmicrotech.com

OPERATING

CONSIDERATIONS

SA56

GENERAL

Please read Application Note 1 "General Operating Consid-

erations" which covers stability, power supplies, heat sinking,
mounting, and specification interpretation. Visit www.apexmi-
crotech.com for design tools that help automate tasks such as
calculations for stability, internal power dissipation, current limit,
heat sink selection, Apex's complete Application Notes library,
Technical Seminar Workbook and Evaluation Kits.

GROUND PINS

There are 4 GND pins. Pins 9 & 10 are for input signal GND

and pins 1 and 23 are for power gnd.

POWER SUPPLY BYPASSING

Bypass capacitors to power supply terminals Vs and V

must be connected physically close to the pins to prevent
erratic, low efficiency operation and excessive ringing at the
outputs. Electrolytic capacitors, at least 10µF per output amp,
are required for suppressing Vs to PGND noise. High qual-
ity ceramic capacitors (X7R) 1µF or greater should also be
used. Only capacitors rated for switching applications should
be considered.

The bypass capacitors must be located as close to the power

supply pins as possible (due to the very fast switching times
of the outputs, the inductance of 1 inch of circuit trace could
cause noticeable degradation in performance). The bypassing
requirements of V

are less stringent, but still necessary. A

0.1µF to 0.47µF capacitor connected directly between the V

and GND (SIG) pins will suffice.

PIN DESCRIPTIONS

Pin #

Name

Description

1,23

PGND

Power ground, high current ground
return path of the motor.

2,3

Bout

Half bridge output B

4,5,19,20 VS

High voltage supply

SCin

Short circuit detect, CMOS. This pin
can be used as a flag for a short cir-
cuit condition. Under normal operation
this pin will be logic low. When a short
circuit is detected, or output current
exceeds approximately 10A, this pin
will change to logic high and the output
will be latched off. Grounding this pin
disables short circuit protection. This
pin should be left open if short circuit
protection is desired but the flag is not
used. Short circuit protection functions
independently of programmable current
limit (ISEN). It is nessesary to bypass
the SCin pin with a 14-47pF ceramic
capacitor. This capacitor will add a de-
lay to the short circuit response but the
device will still be able to protect itself
against short circuit and over current.

TLIM

Temperature limit, CMOS. This pin can
be used as a flag for an over temperature
condition. Under normal operation this
pin will be logic low. When junction tem-
perature exceeds approximately 160°C
this pin will change to logic high and
the output will be latched off. Ground-
ing this pin disables over temperature
protection. This pin should be left open
if over temperature protection is desired
but the flag is not used.

ISEN/ /ILIM Current Sense output and program-

mable current limit. A current propor-
tional to output current is sourced by
this pin. Typically this pin is connected
to a resistor for programmable current
limit or transconductance operation.

9,10

GND(Sig) Ground connection for all internal digital

and low current analog circuitry.

FAULT

Protection circuit flag output, CMOS.
The fault pin will be logic high when the
output MOSFETs have been automati-
cally latched off because of a short circuit
or over temperature condition. This pin
should be left open if not used.

CPWM

An external timing capacitor is connected
to this pin to set the frequency of the
internal oscillator and ramp generator
for analog control mode. The capaci-
tor value (pF) = 4.05x10

, where

= the desired switching frequency.

This pin is grounded for digital control
mode.

13,14

VDD

5V supply for input logic and low voltage
analog circuitry.

VREF

Reference voltage. Can be used at
low current for biasing analog loop
circuits.

DIR

Direction logic input, CMOS/TTL. De-
termines the active output MOSFETs
in two quadrant digital control mode.
This pin should be grounded for analog
control mode.

PWM

CMOS/TTL input for digital PWM con-
trol, or 1-4V analog input for duty cycle
control in analog control mode.

DISABLE Disable logic input, CMOS/TTL. Logic

low on this pin allows the SA56 to func-
tion normally. When pulled to logic high,
all four output MOSFETs are disabled.
Pulling this pin high, then low will reset
a latched fault condition caused by a
short circuit or over temperature fault.

21,22

Aout

Half bridge output A

APEX MICROTECHNOLOGY CORPORATION · 5980 NORTH SHANNON ROAD · TUCSON, ARIZONA 85741 · USA · APPLICATIONS HOTLINE: 1 (800) 546-2739

OPERATING

CONSIDERATIONS

SA56

MODES OF OPERATION

The following chart shows the four modes of operation.

Mode

CPWM

PWM

DIR

Aout

Bout

Quad

Digital

GND

Modu-

lation

High

PWM

Quad

Digital

GND

Modu-

lation

Low

PWM

High

Quad

Digital

GND

High

Modu-

lated

DIR

Quad

Analog

Add

Cap. to

set

Fre-

quency

Drive

with

analog

signal

Not

used

but

GND

Greater

than 50%
high for a

low

input

Greater

than 50%
high for a

high

input

ANALOG INPUT OPERATION

The SA56 can operate with analog or digital inputs. In the

analog mode, the capacitor from CPWM to GND (SIG) sets
the frequency of an internal triangular ramp signal. An analog
input at the PWM pin is compared to the ramp to generate
the duty cycle of the output. In Analog mode, the digital input
on the DIR pin is ignored, though this pin should never be
left floating.

OPERATING WITH DIGITAL INPUTS

Two and 4 quadrant operation are possible with the SA56

when driven with a digital PWM signal from a microcontroller or
DSP. When using a digital modulation signal, tie the CPWM pin
to GND to disable the internal oscillator and ramp generator.

When operating in the digital mode, pulse widths should be

no less than 100ns and the switching frequency should remain
less than 500KHz. This will allow enough time for the output
MOSFETs to reach their full on/off state before receiving a
command to reverse state.

2 QUADRANT DIGITAL MODE

For sign/magnitude (2 quadrant) operation, two digital input

signals are required. A digital PWM signal to the PWM pin can
control the output duty cycle at one output pin with the other
output pin held "HIGH". The digital input on the DIR pin will
control direction by selecting the outputs that switch accord-
ing to the PWM input. If DIR is a logic "HIGH", the A output
will be held "HIGH" and the B output will be switched as the
inverse of the PWM input signal. If DIR is logic "LOW", the B
output will be held "HIGH" and the A output will be switched.
Operating in 2 quadrant mode reduces switching noise and
power dissipation, but limits the control of the motor at very
low speed.

A braking function can be achieved by holding the PWM input

"LOW", which will turn both of the upper MOSFETs on, rapidly
reducing the circulating current of the motor winding.

4 QUADRANT DIGITAL MODE

During 4 quadrant operation a single digital PWM input in-

cludes magnitude and direction information. The digital PWM
input signal is applied to the DIR pin and the PWM/INPUT pin
is tied to "HIGH". Both pairs of output MOSFETs will switch
in a locked anti-phase fashion from 0-100% duty cycle. With
a 50% duty cycle the average voltage of each output will be
half of Vs, and the differential voltage applied to the load will
be zero. Four quadrant operation allows smooth transitions
through zero current for position servos and low speed ap-
plications. Power dissipation is slightly higher since all four
output MOSFETs switch every cycle.

APEX MICROTECHNOLOGY CORPORATION · TELEPHONE (520) 690-8600 · FAX (520) 888-3329 · ORDERS (520) 690-8601 · EMAIL prodlit@apexmicrotech.com

This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.

PROTECTION CIRCUITS

Thermal and short circuit protection are included in the

SA56 to prevent damage during fault conditions. High current
protection circuits will sense a direct short from either output
to GND or Vs as well as across the load. The thermal protec-
tion will engage when the temperature of the MOSFETs reach
approximately 160°C. The FAULT output pin will go "HIGH" if
either protection circuits engages and will place all MOSFETs
in the "OFF" state (high impedance output). The SC or T

LIM

output will also go "HIGH", to indicate which of the protection
features has been triggered. The fault going high disables the
4 output transistors. To reset the fault condition, cycle the V

power or bring the DISABLE pin "HIGH" then "LOW".

The most severe condition for any power device is a direct,

hard-wired ("screwdriver") short from an output to ground.
While the short circuit protection will latch the output MOSFETs
within 250ns (typical) the die and package may be required
to dissipate up to 600 Watts of power until the protection is
engaged. This energy can be destructive, particularly at higher
operating voltages, so good thermal design is critical if such
fault tolerance is required of the system.

PROGRAMMABLE CURRENT LIMIT

The ISEN pin sources a current proportional to the forward

output current of the active P channel output MOSFET. The
proportionality is 300µA (nom) per ampere of output current.
The ISEN output is blocked during the switching transitions
when current spikes can be significant.

To create a programmable current limit, connect a resis-

tor from ISEN out to GND. When the voltage across this
resistor exceeds internally generated 2.75V threshold, all 4
output MOSFETs will be turned off for the remainder of the
switching cycle. A 2.75K resistor will set the current limit to
approximately 5 Amps.

The ISEN output can also be used for maintaining a current

control loop in torque motor applications.

OPERATING

CONSIDERATIONS

SA56

CURRENT SENSE LINEARITY CALCULATION

The current sense linearity is calculated using the method

described below:
a) Define straight line (y = mx + c) joining the two end data

points where, m is the slope and c is the offset or zero
crossover. Calculate the slope m and offset c using the
extreme data points. Assume Isense in the y axis and Iload
in the x axis.

b) Calculate linear Isense (or ideal Isense value, IS

IDEAL

) using

the straight line equation derived in step (a) for the Iload
data points.

c) Determine deviation from linear Isense (step (b)) and actual

measured Isense value (IS

ACTUAL

) as shown below:

IC REV C ERRATA INFORMATION

This document describes the errata information for SA56 rev

C full H-Bridge DC motor driver. Rev C parts can be identified
by date code 0206 marked on the EX package.

Errata Number
and Date

Description

Impact

1
Dated: 3/3/06

TLIM pin:
This pin is mod-
ified to serve
as a flag for
any fault occur-
rence including
short-circuit,
over current
and over tem-
perature.

Impact:
Grounding the TLIM pin
disables all fault protec-
tion mechanisms in the
SA56 including SC, over
current and over temp.
This pin should be left
floating at all times un-
less the user desires
to disable all protection
mechanisms.

Note: The errata items described in the table above are

strictly for beta samples and will be rectified to conform to
SA56U specifications for the production parts.

Part Number SA56