LB1845 SANYO | Alldatasheet

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Technical content

Features

  • PWM current control (fixed off time scheme)
  • Digital load current selection function
  • Sustained output voltage: 45 V
  • Built-in thermal shutdown circuit Package Dimensions unit: mm 3147A-DIP28H Monolithic Digital IC D3096HA (OT) No. 5505-1/7 SANYO: DIP28H [LB1845] SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN PWM Current Control Stepping Motor Driver LB1845 Parameter Symbol Conditions Ratings Unit Motor supply voltage V BB 45 V Peak output current I OPEAK tW = 20 µS 1.75 A Continuous output current I OMAX 1.5 A Logic block supply voltage V CC 7.0 V Logic input voltage range V IN –0.3 to VCC V Emitter output voltage V E 1.0 V Allowable power dissipation Pd max1 Independent IC 3.0 W Pd max2 With an arbitrarily large heat sink 20.0 W Operating temperature Topr –20 to +85 °C Storage temperature Tstg –55 to +150 °C Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Unit Motor supply voltage V BB 10 to 44.5 V Logic block supply voltage V CC 4.75 to 5.25 V Reference voltage V REF 1.5 to 7.5 V Recommended Operating Ranges at Ta = 25°C

No. 5505-2/7 LB1845 Parameter Symbol Conditions Ratings Unit min typ max [Output Block] Output stage supply voltage IBB ON 12 16 mA IBB OFF 0.7 0.9 mA VO (sat)1 IO = +1.0 A sink 1.2 1.4 V Output saturation voltage 1 VO (sat)2 IO = +1.5 A sink 1.4 1.7 V VO (sat)3 IO = –1.0 A source 1.1 1.3 V VO (sat)4 IO = –1.5 A source 1.3 1.6 V Output leakage current IO (leak)1 VO = VBB sink 50 µA IO (leak)2 VO = 0 V source –50 µA Sustained output voltage V(sus) * 45 V [Logic Block] Logic supply current ICC ON I0 = 0.8 V, I1 = 0.8 V 19.5 25.3 mA ICC OFF I0 = 2.4 V, I1 = 2.4 V 15.5 20.1 mA Input voltage VIH 2.4 V VIL 0.8 V Input current IIH VIH = 2.4 V 10 µA IIL VIL= 0.8 V –10 µA I0 = 0.8 V, I1 = 0.8 V 9.5 10 10.5 Current control threshold voltage VREF /VSENSE I0 = 2.4 V, I1 = 0.8 V 13.5 15 16.5 I0 = 0.8 V, I1 = 2.4 V 25.5 30 34.5 Thermal shutdown temperature TS 170 °C Electrical Characteristics at Ta = 25°C, VBB = 38 V, VCC = 5 V, VREF = 5 V Truth Table Pin Assignment Note: *Design guaranteed value Note: Outputs go off when ENABLE is high or in the I0 = I1 = high state. ENABLE PHASE OUT A OUT B L H H L L L L H H — OFF OFF I0 I1 Output current L L VREF / (10 · R E) = IOUT H L VREF / (15 · R E) = IOUT · 2/3 L H VREF / (30 · R E) = IOUT · 1/3 H H 0

Application Circuit Diagram No. 5505-3/7 LB1845

Timing chart for pin switching operations during PWM drive Figure 1 Switching Waveforms toff:Output off time. Determined by external capacitor and resistor Ct and Rt. (toff = Ct · Rt) td: Delay time between the point the set current is sensed at the SENSE pin and the point the output turns off. No. 5505-4/7 LB1845 Pin no. Pin Function 1, 14 VBB Output stage power-supply voltage 2 SENSE1 Set current detection pins. 13 SENSE2 Connect these pins, fed back through noise filters, to E1 and E2. 3 E1 The set current is controlled by the resistors Re inserted between these pins and ground. 12 E2 4, 11 D-GND Internal diode anode connection

6 OUT 1B Outputs

7 OUT 1A

8 OUT 2B

9 OUT 2A

15 GND Ground

27 RC1 Used to set the output off time for the switched output signal. 16 RC2 The fixed off times are set by the capacitors and resistors connected to these pins. toff = CR.

26 VREF 1 Output current settings

17 VREF 2 The output current is determined by the voltage (in the range 1.5 to 7.5 V) input to these pins. 25 PHASE1 Output phase switching inputs.

18 PHASE2 High-level input: OUT A = high, OUT B = low

Low-level input: OUT A = low, OUT B = high

24 ENABLE1 Output on/off settings

19 ENABLE2 High-level input: output off

Low-level input: output on 22, 23 I01, I11 Digital inputs that set the output current 21, 20 I02, I12 The output currents can be set to 1/3, 2/3, or full by setting these pins to appropriate combinations of high and low levels.

28 VCC Logic block power supply

1.External diode Since this IC adopts a system based on lower side transistor switching drive, an external diode for the regenerative current that occurs during switching is required between V BB and VOUT . Use a Schottky barrier diode with a low feedthrough current. 2.Noise filters Since spike noise (see Figure 1) occurs when switching to the on state due to the external diode’s feedthrough current, applications must remove noise from the SENSE pin with a noise filter (Cc, Rc) between the E pin and the SENSE pin. However, note that if the values of Cc and Rc are too large, the SENSE voltage rise will be slowed, and the current setting will be shifted towards a higher current level. 3.V REF pin It is possible to change the output current continuously by continuously changing the VREF pin voltage. However, this voltage cannot be set to 0 V. The VREF pin input impedance is 26 kΩ (±30%) when VREF is 5 V. Since this pin is used to set the output current, applications must be designed so that noise does not appear on this pin's input. 4.GND pin Since this IC switches large currents, care must be taken to avoid ground loops when the IC is mounted in the application. The section of the PCB that handles large currents should be designed with a low-impedance pattern, and must be separated from the small signal sections of the circuit. In particular, the ground for the sense resistor Re must be as close as possible to the IC ground. 5.Operation in hold mode There are cases where a current somewhat larger than the current setting may flow in hold mode (light load mode). Since this IC adopts a lower side switching, lower side sense system, the emitter voltage falls and the sense voltage goes to 0 when the switching state goes to off. The circuit then always turns the output on after the toff period has elapsed. At this time, due to the light load, the existence of the time td, and the fact that the output goes on even if the output current is higher than the set current, the output current will be somewhat higher than the set current. Applications should set the current setting somewhat lower than required if this occurs. 6.Function for preventing the upper and lower outputs being on at the same time This IC incorporates a built-in circuit that prevents the through currents that occur when the phase is switched. The table lists the output on and off delay times when PHASE and EANBLE are switched. 7.1-2 phase excitation and the double 1-2 phase excitation control sequence To reduce the vibration that occurs when the motor turns, this IC supports 1-2 phase excitation and double 1-2 phase excitation by using the output current setting digital input pins I0 and I1 without changing the V REF pin voltage. Tables 1 and 2 list that control sequence, and Figure 2 and Figure 3 present the composite vector diagram for this sequence.2. Noise filters No. 5505-5/7 LB1845 Sink side Source side When PHASE is switched On delay time 10 µs 9 µs Off delay time 1.5 µs 3 µs When ENABLE is on On delay time 9 µs 9 µs Off delay time 1.5 µs 6.5 µs No. Phase A Phase B PH1 I11 I01 Current valuePH2 I12 I02 Current value 0 0 0 0 1 * 1 1 0 1 0 0 1 2/3 0 0 1 2/3 2 * 1 1 0 0 0 0 1 3 1 0 1 2/3 0 0 1 2/3 4 1 0 0 1 * 1 1 0 5 1 0 1 2/3 1 0 1 2/3 6 * 1 1 0 1 0 0 1 7 0 0 1 2/3 1 0 1 2/3 Table 1 [1-2 phase excitation] 1/2 step ENABLE1 = ENABLE2 = 0

No. 5505-7/7 LB1845 This catalog provides information as of December, 1996. Specifications and information herein are subject to change without notice. n No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. n Anyone purchasing any products described or contained herein for an above-mentioned use shall: À Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: \` Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. n Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties.