Document
L6228Q
DMOS driver for bipolar stepper motor
Features
■ Operating supply voltage from 8 to 52 V ■ 2.8 A output peak current (1.4 Ar.m.s.) ■ RDS(on) 0.73 Ω typ. value @ TJ = 25 °C ■ Operating frequency up to 100 kHz ■ Non dissipative overcurrent protection ■ Dual independent constant tOFF PWM current
controllers ■ Fast/slow decay mode selection ■ Fast decay quasi-synchronous rectification ■ Decoding logic for stepper motor full and half-
step drive ■ Cross conduction protection ■ Thermal shutdown ■ Undervoltage lockout ■ Integrated fast free wheeling diodes
Applications
■ Bipolar stepper motor Figure 1. Block diagram
Datasheet − production data
VFQFPN32 5 mm x 5 mm
Description
The L6228Q is a DMOS fully integrated stepper motor driver with non-dissipative overcurrent protection, realized in BCD multipower technology, which combines isolated DMOS power transistors with CMOS and bipolar circuits on the same chip. The device includes all the circuitry needed to drive a two-phase bipolar stepper motor including: a dual DMOS full-bridge, the constant off-time PWM current controller that performs the chopping regulation and the phase sequence generator, that generates the stepping sequence. Available in VFQFPN32 5 mm x 5 mm package, the L6228Q features a non-dissipative overcurrent protection on the high-side power MOSFETs and thermal shutdown.
VBOOT VCP
EN CONTROL HALF/FULL
CLOCK RESET CW/CCW
VBOOT CHARGE PUMP
THERMAL PROTECTION
OCDA OCDB
STEPPING SEQUENCE GENERATION
VOLTAGE REGULATOR
10V 5V
VBOOT
VBOOT
VSA
OVER CURRENT DETECTION
10V
GATE LOGIC
ONE SHOT MONOSTABLE
OVER CURRENT DETECTION
GATE LOGIC
OUT1A OUT2A 10V
PWM
MASKING TIME
+
SENSE
-
COMPARATOR
BRIDGE A
BRIDGE B D01IN1225
SENSEA
VREFA
RCA
VSB OUT1B OUT2B SENSEB VREFB RCB
January 2013
This is information on a product in full production.
Doc ID 14321 Rev 5
1/32
www.st.com
32
Contents
Contents
L6228Q
1
Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2
Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4
Circuit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1 Power stages and charge pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.2 Logic inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3 PWM current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4..