SA60_10 Datasheet, PDF (4/6 Pages) Cirrus Logic – H-Bridge Motor Driver/Amplifiers

SA60
®
Product Innovation From
EXTERNAL CONNECTIONS
1 2 3 4 5 6 7 8 9 10 11 12
*
*
CF
‡
‡
ANALOG DISABLE
NC
Vcc
GND
PWM
INPUT
ANALOG
INPUT
POWER
GND
ISENSE A _*
A OUT
* ^{ISENSE B}
B OUT
‡ Required RC network. See paragraph
+Vs
on transient shutdown.
* Protection diodes are recommended for
applications where +Vs exceeds 50V.
12-pin Power SIP
PACKAGE
STYLE DP
Formed Leads Available
See package style EE
TYPICAL APPLICATION
A wide variety of loads can be driven in either the voltage
mode or the current mode. The most common applications
use three external blocks: a low pass filter converting pulse
11
9
SA60
LOAD
width data to an analog output, a difference amplifier to
4
8
monitor voltage or current and an error amplifier. Filter in-
3
12
ductors must be suitable for square waves at the switching
2
frequency (laminated steel is generally not acceptable). Fil-
ter capacitors must be low ESR and rated for the expected
ripple current. A difference amplifier with gain of less than
one translates the differential output voltage to a single feedback voltage. Dashed line connections and a higher
gain difference amplifier would be used for current control. The error amplifier integrates the difference between the
input and feedback voltages to close the loop.
GENERAL
Please read Application Note 30 on "PWM Basics". Refer to Application Note 1 "General Operating Considerations"
for helpful information regarding power supplies, heat sinking and mounting. Visit www.Cirrus.com for design tools
that help automate pwm filter design; heat sink selection; Apex Precision Power’s complete Application Notes li-
brary; Technical Seminar Workbook; and Evaluation Kits.
PWM OSCILLATOR – INTERNAL OR EXTERNAL
The SA60 contains an internal PWM oscillator whose frequency is determined by an external capacitor connected
between pin 1 and pin 2. Maximum frequency is 125 kHz. The user may also disregard the internal PWM oscillator
and supply the SA60 with an external TTL pulse generator up to 250KHZ.
PIN DESCRIPTION
V_CC - is the low voltage supply for powering internal logic and drivers for the lowside and highside MOSFETS. The
supplies for the highside drivers are derived from this voltage.
V_S - is the higher voltage H-bridge supply. The MOSFETS obtain the output current from this supply pin. The voltage
on this pin is limited to +80V by the drive IC. The MOSFETS are rated at 100 volts.
ISENSE A & B - These are tied to power gnd directly or through sense resistors.
ANALOG GND - is the reference for the internal PWM oscillator. Connect this pin to pin 6. Connect low side of Vcc
supply and any other supply used to generate analog input signals to ANALOG GND.
ANALOG INPUT - is an analog input for controlling the PWM pulse width of the bridge. A voltage higher than Vcc/2
will produce greater than 50% duty cycle pulses out of B OUT. A voltage lower than Vcc/2 will produce greater
than 50% duty cycle pulses out of A OUT. If using in the digital mode, bias this point at 1/2 the logic high level.
DISABLE - Is the connection for disabling all 4 output switches. DISABLE high overrides all other inputs. When
taken low, everything functions normally. An internal pullup to Vcc will keep DISABLE high if pin left open.
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SA60U