PBL3775-1

PBL3775-1 ERICSSON | Alldatasheet

Document overview

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Technical content

22-pin plastic DIP package 24-pin SO package Key Features

• Dual chopper driver in a single package.
• Operation down to -40°C.
• 750 mA continuous output current per channel.
• Low power dissipation, 2.0 W at 2 x 500 mA output current.
• Close matching between channels for high microstepping accuracy.
• Digital filter on chip eliminates external filtering components.
• Plastic 22-pin batwing DIL package, 24-pin SOIC batwing or 28-pin power PLCC. All with lead-frame for heatsinking through PC board copper. PBL 3775/1 Dual Stepper Motor Driver

Description

The PBL 3775/1 is a switch-mode (chopper), constant-current driver IC with two channels, one for each winding of a two-phase stepper motor. The circuit is similar to Ericsson´s PBL 3773/1. While several of Ericsson´s dual stepper motor drivers are optimized for micro-stepping applications, PBL 3775/1 is equipped with a disable input to simplify half-stepping operation. The PBL 3775/1 contains a clock oscillator, which is common for both driver channels, a set of comparators and flip-flops implementing the switching control, and two output H-bridges, including recirculation diodes. Voltage supply requirements are + 5 V for logic and + 10 to + 45 V for the motor. The close match between the two driver channels guarantees consistent output current ratios and motor positioning accuracy. PBL3775/1 PBL3775/1 RC PBL 3775/1 M A1 M B1 M B2 M A2 GNDC 2V R2Phase 2 VCC C 1VR1Phase 1 E 1 E 2 VCC S R Q Logic S R Q+ Logic V MM2 V MM1 Dis1 Dis2 Figure 1. Block diagram

Figure 3. Definition of terms.Figure 2. Definition of symbols.

1 D = tton off+

Electrical Characteristics

Electrical characteristics over recommended operating conditions, unless otherwise noted. - 20° C ≤ Tj ≤ + 125° C. Ref. Parameter Symbol fig. Conditions Min Typ Max Unit General Supply current I CC 2 Note 4. 55 70 mA Supply current I CC 2 Dis 1= Dis2= HIGH. 7 10 mA Total power dissipation P D 8V MM = 24 V, IM1 = IM2 = 500 mA. 2.0 2.3 W Notes 2, 3, 4. Total power dissipation P D 8V MM = 24 V, IM1 = 700 mA, IM2 = 0 mA. 1.7 2.0 W Notes 2, 3, 4. Thermal shutdown junction temperature 160 °C Turn-off delay t d 3T A = +25°C, dVC /dt ≥ 50 mV/µs, 1.1 2.0 µs IM = 100 mA. Note 3. Logic Inputs Logic HIGH input voltage V IH 2 2.0 V Logic LOW input voltage V IL 2 0.6 V Logic HIGH input current I IH 2V I = 2.4 V 20 µA Logic LOW input current I IL 2V I = 0.4 V -0.2 -0.1 mA Analog Inputs Threshold voltage V CH 2V R =5 V 480 500 520 mV Input current I A 2V R = 5 V 500 µA |VC1 —V C2 | mismatch V Cdiff 21 m V Motor Outputs Lower transistor saturation voltage 10 IM = 500 mA 0.4 0.8 V Lower transistor leakage current 2 V MM =41 V,TA = +25°C. Dis1= Dis2= HIGH. 100 µA Lower diode forward voltage drop 11 IM = 500 mA 1.1 1.3 V Upper transistor saturation voltage 12 IM = 500 mA. 1.1 1.4 V Upper diode forward voltage drop 13 IM = 500 mA. 1.1 1.4 V Upper transistor leakage current 2 V MM =41 V,TA = +25°C. Dis1= Dis2= HIGH.. 100 µA Chopper Oscillator Chopping frequency f s 3C T = 4 700 pF, RT = 12 kohm 21.5 23.0 24.5 kHz Digital filter blanking time tb 3C T = 4 700 pF. Note 3. 1.0 µs Thermal Characteristics Ref. Parameter Symbol fig. Conditions Min Typ Max Unit Thermal resistance Rth J-BW DIL package. 11 °C/W RthJ-A 14 DIL package. Note 2. 40 °C/W RthJ-BW PLCC package. 9 °C/W RthJ-A 14 PLCC package. Note 2. 35 °C/W Rthj-c SO package 13 °C/W Rthj-a SO package 42 °C/W Notes 1. All voltages are with respect to ground. Currents are positive into, negative out of specified terminal. 2. All ground pins soldered onto a 20 cm2 PCB copper area with free air convection, TA = + 25° C. 3. Not covered by final test program. 4. Switching duty cycle D = 30 %, f s = 23.0 kHz.

2 1 [8] M B1 Motor output B, channel 1. Motor current flows from MA1 to MB1 when Phase1 is HIGH. 3 2 [10] E 1 Common emitter, channel 1. This pin connects to a sensing resistor RS to ground. 4 3 [11] M A1 Motor output A, channel 1. Motor current flows from MA1 to MB1 when Phase1 is HIGH. 5 4 [12] V MM1 Motor supply voltage, channel 1, +10 to +40 V. VMM1 and VMM2 should be connected together. 6,7 5, 6, [1-3, 9, GND Ground and negative supply. Note: these pins are used thermally for heat-sinking. 28] for efficient heat sinking. resistor, filtered by the internal digital filter or an optional external RC network. flows from MA1 to MB1 when Phase1 is HIGH. in a rapidly decreasing output current to zero. to obtain the nominal switching frequency of 23.0 kHz and a digital filter blanking time of 1.0µs. 13 12 [23] V CC Logic voltage supply, nominally +5 V. in a rapidly decreasing output current to zero. flows from MA2 to MB2 when Phase2 is HIGH. resistor, filtered by the internal digital filter or an optional external RC network. MM2 Motor supply voltage, channel 2, +10 to +40 V. VMM1 and VMM2 should be connected together. 21 20 [5] M A2 Motor output A, channel 2. Motor current flows from MA2 to MB2 when Phase2 is HIGH. 22 21 [6] E 2 Common emitter, channel 2. This pin connects to a sensing resistor RS to ground. 23 22 [7] M B2 Motor output B, channel 2. Motor current flows from MA2 to MB2 when Phase2 is HIGH. Figure 4. Pin configuration.

Figure 6. Typical stepper motor driver application with PBL 3775/1.Figure 5. Output stage with current paths during turn-on, turn-off and phase shift. sensing resistor during turn-on. off and phase shift are shown in figure 5. ignored during the blanking time.

transients by selecting a proper CT value. which gives a blanking time of 1.0 µs. the Dis input should be HIGH. the iron losses in the motor. decreasing output current to zero. consists of closely matched resistors. Nominal input reference voltage is 5 V.

• Use separate ground leads for power ground (the ground connection of R S), the ground leads of PBL 3775/1, and the ground of external analog and digital circuitry. The grounds should be connected together close to the GND pins of PBL 3775/1.
• Decouple the supply voltages close to the PBL 3775/1 circuit. Use a ceramic capacitor in parallel with an electrolytic type for both V CC and VMM . Route the power supply lines close together.
• Do not place sensitive circuits close to the driver. Avoid physical current loops, and place the driver close to both the motor and the power supply connector. The motor leads could preferably be twisted or shielded. Motor selection The PBL 3775/1 is designed for two- phase bipolar stepper motors, i.e. motors that have only one winding per phase. The chopping principle of the PBL 3775/1 is based on a constant frequency and a varying duty cycle. This scheme imposes certain restrictions on motor selection. Uns- table chopping can occur if the chopping duty cycle exceeds approxi- mately 50 %. See figure 3 for definitions. To avoid this, it is necessary to choose a motor with a low winding resistance and inductance, i.e. windings with a few turns. It is not possible to use a motor that is rated for the same voltage as the actual supply voltage. Only rated current needs to be considered. Typical motors to be used together with the PBL 3775/1 have a voltage rating of 1 to 6 V, while the supply voltage usually ranges from 12 to 40 V.

Figure 7. Half stepping system where PBD 3517/1 is used as controller circuit in order to generate the necessary sequence to the PBL 3775/1.