LM621N

LM621 NSC | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 12

Technical content

Features

Y Adjustable dead-time feature eliminates current spiking Y On-chip clock oscillator for dead-time feature Y Outputs drive bipolar power devices (up to 35 mA base current) or MOSFET power devices Y Compatible with three- and four-phase motors . . . Ð Bipolar drive to delta- or Y-wound motors Ð Unipolar drive to center-tapped Y-wound motors Ð Supports 30- and 60-degree shaft position sensor placements for three-phase motors Ð Supports 90-degree sensor placement for four-phase motors Y Directly interfaces to pulse-width modulator output(s) via OUTPUT INHIBIT (PWM magnitude) and DIREC- TION (PWM sign) inputs Y Direct interface to Hall sensors Y Outputs are current limited Y Undervoltage lockout Connection Diagram TL/H/8679–1 Order Number LM621N See NS Package Number N18A C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings (See Notes) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. V CC1 a7V VCC2 a45V Logic Inputs (Note 1) V CC1 a0.5V, b0.5V Logic Input Clamp Current 20 mA Output Voltages a45V, b0.5V Output Currents Internally current limited Operating Ambient Temperature Range LM621 b40§Ct o a85§C Storage Temperature Range b65§Ct o a150§C Junction Temperature 150 §C ESD Susceptibility (Note 10) 2000V Lead Temperature, N pkg. (Soldering, 4 sec.) 260 Electrical Characteristics (See Notes) Parameter Conditions Typ Tested Design UnitsLimits Limits DECODER SECTION High Level Input Voltage HS1, HS2, HS3: 2.0 2.0 V min 30/60 SELECT: 2.0 2.0 V min High Level Input Current HS1, HS2, HS3: V IH e VCC1 100 200 mA max 30/60 SELECT: V IH e VCC1 120 240 mA max Low Level Input Voltage HS1, HS3 and HS2 30/60 e 5V 0.6 0.4 V max HS1, HS3 and HS2 30/60 e 0V 0.6 0.4 V max 30/60 Select H SI e HS3 e 5V 0.6 0.4 Vmax Low Level Input Current HS1 and HS3: V IL e 0.35V b400 b600 mA max HS2: V IL e 0.4V b100 b200 mA max 30/60 SELECT V IL e 0.0V b700 b1000 mA max Input Clamp Voltage I in e 1m A ( V CC1 a 0.7) V (Pins 2, 3, 5, 6, 7, 8, 17) I in eb 1m A ( b0.6) V Output Leakage Current Outputs Off Sinking Outputs V CC2 e 40V, 0.2 1.0 mA VOUT e 40V Sourcing Outputs V OUT e 0V b0.2 b1.0 mA Short-Circuit Current V CC2 e 10V, 50 35 mA min Sinking Outputs V OUT e 10V Sourcing Outputs V OUT e 0V b50 b35 mA min Vsat (sinking) I e 20 mA 0.83 1.00 V max Vdrop (sourcing) e (VCC2 b VOUT)I eb 20 mA 1.7 2.00 V max Output Rise Time (sourcing) 50 ns CL k 10 pF Output Fall Time (sinking) 50 ns CL s 10 pF Propagation Delay Dead-Time Off 200 ns (Hall Input to Output)

Electrical Characteristics (See Notes) (Continued) Parameter Conditions Typ Tested Design UnitsLimits Limits DEAD-TIME SECTION High Level Input Voltage DIRECTION: Pin 3 e 0V 2.0 2.0 V min OUTPUT INHIBIT: 2.0 2.0 V min DEAD-TIME ENABLE: Pin 17 e 0V 2.0 2.0 V min High Level Input Current V in e 5V DIRECTION: Pin 3 e 0V 100 150 mA max OUTPUT INHIBIT: 60 100 mA max DEAD-TIME ENABLE: 200 300 mA max Low Level Input Voltage DIRECTION: Pin 3 e 0V 0.6 0.4 V max OUTPUT INHIBIT: 0.6 0.4 V max DEAD-TIME ENABLE: 0.3 0.2 V max Low Level Input Current DIRECTION: V in e 0.6V b100 b150 mA max OUTPUT INHIBIT: V in e 0.6V b60 b100 mA max DEAD-TIME ENABLE: V in e 0V b200 b300 mA max Propagation Delays Dead-Time Off, (Inputs to Outputs) (Pin 3 e 0V) OUTPUT INHIBIT 200 ns DIRECTION 200 ns Minimum Clock Period, R e 11 k X,R 1 e 1k 1.8 msTCLK (Notes 3, 11) C e 200 pF Clock Accuracy R e 30k, R 1 e 1k g3%f e 100 kHz (Note 11) C e 420 pF Minimum Dead-Time Dead-Time Off 15 ns Minimum Dead-Time Dead-Time On 2 T CLK COMPLETE CIRCUIT Total Current Drains Outputs Off ICC1 10 mA min ICC1 15 22 30 mA max ICC2 VCC2 e 40V 2 mA min ICC2 36 9 mA max Undervoltage Lockout 3.6 3.0 V MAXVCC1 Note 1. Unless otherwise noted ambient temperature (T A) e 25§C. Note 3. The clock period is typically T CLK e (0.756 c 10b3)( R a 1) C, where T CLK is in ms ,Ri si nk X, and C is pF. Also see selection graph in Typical Characteristics for determining values of R and C. Note that the value of R should be no less than 11 k X and C no less than 200 pF. Note 4. Tested limits are guaranteed and 100% production tested. Note 5. Design limits are guaranteed (but not 100% production tested) at the indicated temperature and supply voltages. These limits are not used to calculate outgoing quality levels. Note 6. Specifications in boldface apply over junction temperature range of b40§Ct o a85§C. Note 7. Typical Thermal Resistances O JA (see Note 8): N pkg, board mounted 110 §C/W N pkg, socketed 118 §C/W Note 8. Package thermal resistance indicates the ability of the package to dissipate heat generated on the die. Given ambient temperature and power dissipation, the thermal resistance parameter can be used to determine the approximate operating junction temperature. Operating junction temperature directly effects product performance and reliability. Note 9. This part specifically does not have thermal shutdown protection to avoid safety problems related to an unintentional restart due to thermal time constant variations. Care should be taken to prevent excessive power dissipation on the die. Note 10: Human body model, 100 pF, discharged through a 1500 X resistor. Note 11: R 1 e 0 for C t 620 pF.

Typical Performance Characteristics for R and C Selection Graph vs Temperature Supply Currents vs Temperature Supply Currents Vsat vs Temperature V drop vs Temperature ( @ TA e 25§C) Typ. V drop vs I out source Typ. V sat vs I out sink TL/H/8679–2 Description of Inputs and Outputs Pin 1: V CC1 (a5V). The logic and clock power supply pin. Pin 2: DIRECTION. This input determines the direction of rotation of the motor; ie., clockwise vs. counterclockwise. See truth table. Pin 3: DEAD-TIME ENABLE. This input enables or disables the dead-time feature. Connecting a5V to pin 3 enables dead-time, and grounding pin 3 disables it. Pin 3 should not be allowed to float. Pin 4: CLOCK TIMING. An RC network connected between this pin and ground sets the period of the clock oscillator, which determines the amount of dead-time. See Figure 2 and text. Pins 5 thru 7: HS1, HS2, and HS3 (Hall-sensor inputs). These inputs receive the rotor-position sensor inputs from the motor. Three-phase motors provide all three signals; four phase motors provide only two, one of which is con- nected to both HS2 and HS3. Pin 8: 30/60 SELECT. This input is used to select the re- quired decoding for three-phase motors; ie, either ‘‘30-de- gree’’ ( a5V) or ‘‘60-degree’’ (ground). Connect pin 8 to a5V when using a four-phase motor. Pin 9: LOGIC GROUND. Ground for the logic power supply. Pin 10: POWER GROUND. Ground for the output buffer supply. Pins 11 thru 13: SOURCE OUTPUTS. The three current- sourcing outputs which drive the external power devices that drive the motor. Pins 14 thru 16: SINK OUTPUTS. The three current-sinking outputs which drive the external power devices that drive the motor. Pin 17: OUTPUT INHIBIT. This input disables the LM621 outputs. It is typically driven by the magnitude signal from an external sign/magnitude PWM generator. Pin 17 ea 5V e outputs off. Pin 18: V CC2 (a5t o a40V). This is the supply for the collectors of the three current-sourcing outputs (pins 11 thru 13). When driving MOSFET power devices, pin 18 may be connected to a voltage source of up to a40V to achieve sufficient output swing for the gate. When driving bipolar power devices, pin 18 should be connected to a5V to mini- mize on-chip power dissipation. Undervoltage lockout auto- matically shuts down all outputs if the V CC1 supply is too low. All outputs will be off if V CC1 falls below the undervol- tage lockout voltage.

Three-Phase Motor Commutation (Continued) TABLE I. LM621 Commutation Decoder Truth Table Sensor Position Sensor Inputs Sink Outputs Source Outputs Phasing Range H S 1 H S 2 H S 3 123123 0–60 0 0 0 ON off off off ON off 60–120 0 0 1 ON off off off off ON 30 deg 120–180 0 1 1 off ON off off off ON 180–240 1 1 1 off ON off ON off off 240–300 1 1 0 off off ON ON off off 300–360 1 0 0 off off ON off ON off 0–60 1 0 1 ON off off off ON off 60–120 1 0 0 ON off off off off ON 60 deg 120–180 1 1 0 off ON off off off ON 180–240 0 1 0 off ON off ON off off 240–300 0 1 1 off off ON ON off off 300–360 0 0 1 off off ON off ON off 0–90 0 1 HS2 off na off off na ON 90 deg 90–180 0 0 HS2 ON na off off na off 180–270 1 0 HS2 off na ON off na off 270–360 1 1 HS2 off na off ON na off Pin Numbers: 5 6 7 16 15 14 13 12 11 Note 1: The above outputs are generated when the Direction input, pin 2, is logic high. For reverse rotation (pin 2 logic low), the above sink and source output states become exchanged. Note 2: For four-phase motors sink and source outputs number two (pins 15 and 12) are not used; hense the ‘‘na’’ (not applicable) in the appropriate columns above. Figure 6 shows how the required sink and source outputs for four-phase motors are derived. TABLE II. Alternative Sensor-Phasing Names Alternate Position Sensor Inputs Corresponding LM621 Position Phasing Range HS1 HS2 HS3 Range and/or Comments 0–60 0 0 0 Same as 30-degree phasing, but in reverse 60–120 1 0 0 order; i.e., only change is relative direction. ‘‘60 deg’’ 120–180 1 1 0 180–240 1 1 1 240–300 0 1 1 300–360 0 0 1 0–60 0 0 1 Same as 60-degree phasing, but with shifted 60–120 1 0 1 order of position ranges; i.e., only change is ‘‘120 deg’’ 120–180 1 0 0 relative phasing of sensor signals. 180–240 1 1 0 240–300 0 1 0 300–360 0 1 1 0–60 0 1 0 Same comment as above for ‘‘120 deg’’ 60–120 1 1 0 phasing. ‘‘240 deg’’ 120–180 1 0 0 180–240 1 0 1 240–300 0 0 1 300–360 0 1 1 0–60 0 1 1 Same as 30-degree phasing, but with shifted 60–120 1 1 1 order of position ranges, i.e., only change is ‘‘300 deg’’ 120–180 1 1 0 relative phasing of sensor signals. 180–240 1 0 0 240–300 0 0 0 300–360 0 0 1 Four-Phase Motor Commutation Four-phase motors use a 90-degree (quadrature) rotor-posi- tion sensor phasing. This phasing scheme is also shown in Table I. LM621 Commutation Decoder Truth Table. As shown in Table I, the 90-degree phasing has only two rotor- position-sensor signals, HS1 and HS2. When using the LM621 to run a four-phase motor the HS2 signal is connect- ed to both the HS2 and HS3 chip inputs.

FIGURE 5. Commutation of Three-Phase Motor (MOSFET Switches)

FIGURE 7. Half-Wave Drive of Y-Configured Motor

LM621 Brushless Motor Commutator Physical Dimensions inches (millimeters) Lit. Ý 107155 Molded Dual-in-Line Package (N) Order Number LM621N LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or 2. A critical component is any component of a life systems which, (a) are intended for surgical implant support device or system whose failure to perform can into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life failure to perform, when properly used in accordance support device or system, or to affect its safety or with instructions for use provided in the labeling, can effectiveness. be reasonably expected to result in a significant injury to the user. National Semiconductor National Semiconductor National Semiconductor National Semiconductor Corporation Europe Hong Kong Ltd. Japan Ltd.

1111 West Bardin Road Fax: (

a49) 0-180-530 85 86 13th Floor, Straight Block, Tel: 81-043-299-2309 Arlington, TX 76017 Email: cnjwge @ tevm2.nsc.com Ocean Centre, 5 Canton Rd. Fax: 81-043-299-2408 Tel: 1(800) 272-9959 Deutsch Tel: ( a49) 0-180-530 85 85 Tsimshatsui, Kowloon Fax: 1(800) 737-7018 English Tel: ( a49) 0-180-532 78 32 Hong Kong Fran3ais Tel: ( a49) 0-180-532 93 58 Tel: (852) 2737-1600 Italiano Tel: ( a49) 0-180-534 16 80 Fax: (852) 2736-9960 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.