E-PBL3717A STMicroelectronics

PBL3717A STEPPER MOTOR DRIVER .FULL STEP - HALF STEP - QUARTER STEP OPERATING MODE . BIPOLAR OUTPUT CURRENT UP TO 1 A .FROM 10 V UP TO 46 V MOTOR SUPPLY VOLTAGE .LOW SATURATION VOLTAGE WITH INTE- GRATED BOOTSTRAP . BUILT IN FAST PROTECTION DIODES .EXTERNALLY SELECTABLE CURRENT LEVEL .OUTPUT CURRENT LEVEL DIGITALLY OR ANALOGUE CONTROLLED . THERMAL PROTECTION WITH SOFT INTER- VENTION Powerdip 12 + 2 + 2 (Plastic Package) ORDER CODE : PBL3717A DESCRIPTION PIN CONNECTION (top view) The PBL3717A is a monolithic IC which controls and drives one phase of a bipolar stepper motor with chopper control of the phase current. Current levels may be selected in three steps by means of two logic inputs which select one of three current compara- tors. When both of these inputs are high the device is disabled. A separate logic input controls the direc- tion of current flow. A monostable, programmed by an external RC net- work, sets the current decay time. The power section is a full H-bridge driver with four internal clamp diodes for current recirculation. An external connection to the lower emitters is available for the insertion of a sensing resistor. Two PBL3717As and few external components form a complete stepper motor drive subsystem. The raccomended operating ambient temperature ranges is from 0 to 70 C. The PBL3717A is supplied in a 12 + 2 + 2 lead Pow- erdip package. 1/11 July 2003PBL3717A PIN FUNCTIONS N Name Function 1 UTPUT B Output Connection (with pin 15). The output stage is a bridge formed by four transistors and four diodes suitable for switching applications. 2 PULSE TIME A parallel RC network connected to this pin sets the OFF time of the lower power transistors. The pulse generator is a monostable triggered by the rising edge of the output of the comparators (t = 0.69 R C ). off T T 3 SUPPLY VOLTAGE B Supply Voltage Input for Half Output Stage See also pin 14. 4 GROUND Ground Connection. With pins 5, 12 and 13 also conducts heat from die to printed circuit copper. 5 GROUND See pin 4. 6 LOGIC SUPPLY Supply Voltage Input for Logic Circuitry 7 INPUT 1 This pin and pin 9 (INPUT 0) are logic inputs which select the outputs of the three comparators to set the current level. Current also depends on the sensing resistor and reference voltage. See truth table. 8 PHASE This TTL-compatible logic input sets the direction of current flow through the load. A high level causes current to flow from OUTPUT A (source) to OUTPUT B (sink). A schmitt trigger on this input provides good noise immunity and a delay circuit prevents output stage short circuits during switching. 9 INPUT 0 See INPUT 1 (pin 7) . 10 COMPARATOR Input connected to the three comparators. The voltage across the sense resistor INPUT is feedback to this input through the low pass filter R C . The lower power C C transistor are disabled when the sense voltage exceeds the reference voltage of the selected comparator. When this occurs the current decays for a time set by R C , t = 0.69 R C . T T off T T 11 REFERENCE A voltage applied to this pin sets the reference voltage of the three comparators, this determining the output current (also thus depending on R and the two inputs s INPUT 0 and INPUT 1). 12 GROUND See pin 4. 13 GROUND See pin 4. 14 SUPPLY VOLTAGE A Supply Voltage Input for Half Output Stage. See also pin 13. 15 OUTPUT A See pin 1. 16 SENSE RESISTOR Connection to Lower Emitters of Output Stage for Insertion of Current Sense Resistor TRUTH TABLE Input 0 (pin 9) Input 1 (pin 7) H H No Current L H Low Current H L Medium Current L L High Current 2/11