Application Note 1041 The Design Guide for AM4962 Prepared by Zhihong Zhang Design Engineering Dept. 1. Introduction 3.3 Measure Parameter Solder D1, C1, C2, C3 and hall sensor onto the PCB (R1, R2, R3, R4, R5, R6 open); Measure the fan rotating speed vs. input duty, and draw a curve figure accordingly (Step=5%), as Figure 4. The AM4962 is a full wave driver IC with direct PWM control function, which features as below: • Motor Speed Directly Controlled by PWM Pulse • Built-in Triangle Wave Circuit without Extra Oscillation Capacitors • Built-in Hall Bias Circuit • Built-in Minimal Speed Setup Circuit • Slope K* Adjustable • Rotation Speed Indication (FG) • Rotation or Lock State Indication (RD) • Built-in Thermal Shutdown Circuit • Lock Protection and Auto-restart • Output Current Limit 3.4 Adjust Maximum Speed Adjust the maximum speed vs. input duty to approximately match the target specification via R3 and R4; Measure the fan rotating speed vs. input duty, as shown in Table 3. And draw a curve figure accordingly (Step=5%), as Figure 5. 3.5 Adjust Slope K Adjust Slope K of the fan rotating speed vs. input duty to approximately match the target specification via R5 and R6; Measure the fan rotating speed vs. input duty, as shown in Table 4. And draw a curve figure accordingly, as shown in Figure 6. * Slope K is the slope of output PWM duty vs. input PWM duty This application note involves the general description, recommended application steps and typical application examples, which may be helpful to designers in product development process. 3.6 Adjust Minimum Speed Adjust the minimum speed vs. input duty to approximately match the target specification via R2 (R1=15kΩ). Measure the fan rotating speed and the input duty, as shown in Table 5. And draw a curve figure accordingly, as shown in Figure 7. 2. General Description The AM4962 is capable of speed control by PWM pulse. It can be used in applications such as CPU cooler fan in PC and brushless DC motor driver. Note 1: 1) Mutual affections may occur when implementing 3.3 and 3.4. So, repeated adjustments may be needed. 2) About how R1, R2, R3, R4, R5 affect the maximum speed, slope K and minimum speed, please refer to the AM4962 Data Sheet (Page 12 to 13) for details. The AM4962 is available in HTSSOP-14 and SSOP-16 packages. 3. Recommended Application Steps 3.1 Set Up Specification Create a specification for the fan rotating speed vs. input duty (Table 1.), and draw a curve figure accordingly (Figure 1.). 3.2 Create PCB Drawing Make a PCB drawing in accordance with the recommended application circuit, as shown in Figure 2. The soldering pad area contacted with the power ground pin should be as large as possible to ensure good heat dissipation ability. D2 and D3 are recommended to be used when the current in coil L1 is higher than 300mA. A typical PCB application example is shown in Figure 3. Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 1 Application Note 1041 Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 730 1110 1479 0 730 1110 1479 840 5 730 1110 1479 5 730 1110 1479 861 10 730 1110 1479 10 730 1110 1479 898 15 730 1110 1479 15 730 1110 1479 979 20 730 1110 1479 20 730 1110 1479 1060 25 730 1110 1479 25 730 1110 1479 1180 30 730 1110 1479 30 730 1110 1479 1300 35 929 1306 1673 35 929 1306 1673 1445 40 1128 1505 1867 40 1128 1505 1867 1590 45 1372 1701 2063 45 1372 1701 2063 1745 50 1525 1896 2255 50 1525 1896 2255 1900 55 1724 2092 2451 55 1724 2092 2451 2035 60 1922 2287 2642 60 1922 2287 2642 2170 65 2121 2483 2838 65 2121 2483 2838 2325 70 2319 2678 3030 70 2319 2678 3030 2480 75 2518 2874 3224 75 2518 2874 3224 2650 80 2717 3069 3418 80 2717 3069 3418 2820 85 2916 3265 3612 85 2916 3265 3612 2995 90 3114 3460 3806 90 3114 3460 3806 3179 95 3114 3460 3806 95 3114 3460 3806 3350 100 3114 3460 3806 100 3114 3460 3806 3500 Table 1. Specification for Rotating Speed Dec. 2009 Table 2. Test Data (R1, R2, R3, R4, R5, R6 open) Rev. 1. 0 BCD Semiconductor Manufacturing Limited 2 Application Note 1041 Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 730 1110 1479 1453 0 730 1110 1479 850 5 730 1110 1479 1483 5 730 1110 1479 871 10 730 1110 1479 1524 10 730 1110 1479 908 15 730 1110 1479 1523 15 730 1110 1479 994 20 730 1110 1479 1552 20 730 1110 1479 1070 25 730 1110 1479 1616 25 730 1110 1479 1180 30 730 1110 1479 1695 30 730 1110 1479 1272 35 929 1306 1673 1823 35 929 1306 1673 1406 40 1128 1505 1867 1965 40 1128 1505 1867 1572 45 1372 1701 2063 2120 45 1372 1701 2063 1736 50 1525 1896 2255 2280 50 1525 1896 2255 1952 55 1724 2092 2451 2473 55 1724 2092 2451 2146 60 1922 2287 2642 2655 60 1922 2287 2642 2328 65 2121 2483 2838 2820 65 2121 2483 2838 2522 70 2319 2678 3030 3005 70 2319 2678 3030 2707 75 2518 2874 3224 3169 75 2518 2874 3224 2864 80 2717 3069 3418 3320 80 2717 3069 3418 3120 85 2916 3265 3612 3364 85 2916 3265 3612 3264 90 3114 3460 3806 3380 90 3114 3460 3806 3380 95 3114 3460 3806 3416 95 3114 3460 3806 3416 100 3114 3460 3806 3428 100 3114 3460 3806 3428 Table 3. Test Data (R1, R2, R3, R5, R6 open, R4=200kΩ) Dec. 2009 Table 4. Test Data (R1, R2, R3, R6 open, R4=R5=200kΩ) Rev. 1. 0 BCD Semiconductor Manufacturing Limited 3 Application Note 1041 Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 730 1110 1479 1182 5 730 1110 1479 1186 10 730 1110 1479 1194 15 730 1110 1479 1188 20 730 1110 1479 1224 25 730 1110 1479 1228 30 730 1110 1479 1272 35 929 1306 1673 1406 40 1128 1505 1867 1572 45 1372 1701 2063 1736 50 1525 1896 2255 1952 55 1724 2092 2451 2146 60 1922 2287 2642 2328 65 2121 2483 2838 2522 70 2319 2678 3030 2707 75 2518 2874 3224 2864 80 2717 3069 3418 3120 85 2916 3265 3612 3264 90 3114 3460 3806 3350 95 3114 3460 3806 3416 100 3114 3460 3806 3428 Table 5. Test Data (R1=15kΩ, R2=5.125kΩ, R4=R5=200kΩ, R3, R6 open,) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 4 Application Note 1041 4000 Lower Limit Target Upper Limit Rotating Speed (RPM) 3500 3000 2500 2000 1500 1000 500 0 20 40 60 80 100 Input Duty (%) Figure 1. Curves of Rotating Speed vs. Input Duty (Example) VCC D1 L1 V+ D2 D3 AM4962 1 (1) C1 1 F 2 (3) R1 3 (4) 4 (5) R2 R3 5 (6) R4 C3 F OUT2 VCC VMIN PWM OUT1 GND CT RADJ CF HIN- 6 (7) FG HB 7 (8) RD PGND HIN+ 14 (15) V+ 13 (14) 12 (13) R5 11 (12) 10 (11) 9 (10) R6 Hall 8 (9) C2 0.47 F Typical Application (Slope K and Minimum/Maximum Duty Adjustable) Figure 2. Recommended Application Circuit Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 5 Application Note 1041 Figure 3. AM4962 PCB Layout (Example) 4000 4000 Lower Limit Target Upper Limit AM4962 3000 Lower Limit Target Upper Limit AM4962 3500 Rotating Speed (RPM) Rotating Speed (RPM) 3500 2500 2000 1500 1000 3000 2500 2000 1500 1000 500 0 20 40 60 80 500 100 0 Input Duty (%) 40 60 80 100 Input Duty (%) Figure 4. Curves of Rotating Speed vs. Input Duty (R1, R2, R3, R4, R5, R6 open) Dec. 2009 20 Figure 5. Curves of Rotating Speed vs. Input Duty (R1, R2, R3, R5, R6 open, R4=200kΩ) Rev. 1. 0 BCD Semiconductor Manufacturing Limited 6 Application Note 1041 4000 4000 Lower Limit Target Upper Limit AM4962 3000 Lower Limit Target Upper Limit AM4962 3500 Rotating Speed (RPM) Rotating Speed (RPM) 3500 2500 2000 1500 1000 3000 2500 2000 1500 1000 500 500 0 20 40 60 80 100 0 Input Duty (%) Figure 6. Curves of Rotating Speed vs. Input Duty (R1, R2, R3, R6 open, R4=R5=200kΩ) Dec. 2009 20 40 60 80 100 Input Duty (%) Figure 7. Curves of Rotating Speed vs. Input Duty (R1=15 kΩ, R2=5.125 kΩ, R4=R5=200kΩ, R3, R6 open) Rev. 1. 0 BCD Semiconductor Manufacturing Limited 7 Application Note 1041 4. Typical Application Examples 4.1 Application Example 1 4.1.1 Requirement of Customer’s Target Product: (1) Rotating speed remain unchanged under the condition: input duty≤20% (2) When input duty linearly increases from 20% to 100%, the rotating speed linearly increases accordingly. 4.1.2 Customer’s Specification Data Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) 0 500 750 1000 5 500 750 1000 10 500 750 1000 15 500 750 1000 20 500 750 1000 25 662 917.5 1173 30 822 1083 1344 35 980 1248.5 1515 40 1142 1414 1686 45 1302 1579.5 1857 50 1462 1745 2028 55 1622 1910.5 2199 60 1781 2076 2371 65 1941 2241.5 2542 70 2101 2407 2713 75 2261 2572 2884 80 2421 2738 3055 85 2581 2903.5 3226 90 2740 3069 3398 95 2900 3234.5 3569 100 3060 3400 3740 Table 6. Customer’s Specification Data (Application Example 1) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 8 Application Note 1041 4000 Rotating Speed (RPM) 3500 Lower Limit Target Upper Limit 3000 2500 2000 1500 1000 500 0 20 40 60 80 100 Input Duty (%) Figure 8. Specification Curves of Rotating Speed (Application Example 1) 4.1.3 Recommended Application Circuit Application Example 1 (Slope K and Minimum/Maximum Duty Adjustable) Figure 9. Recommended Application Circuit (R1=15kΩ ,R2=5.53kΩ, R5=200kΩ, R3, R4, R6 open, C3=0.22µF) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 9 Application Note 1041 4.1.4 Test Data and Curve Figure Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) FAN1 Rotating Speed (RPM) FAN2 Rotating Speed (RPM) 0 500 750 1000 672 669 5 500 750 1000 675 672 10 500 750 1000 678 675 15 500 750 1000 720 705 20 500 750 1000 765 780 25 662 917.5 1173 870 882 30 822 1083 1344 1005 1020 35 980 1248.5 1515 1164 1197 40 1142 1414 1686 1371 1410 45 1302 1579.5 1857 1542 1587 50 1462 1745 2028 1716 1734 55 1622 1910.5 2199 1845 1884 60 1781 2076 2371 2025 2085 65 1941 2241.5 2542 2202 2286 70 2101 2407 2713 2376 2430 75 2261 2572 2884 2592 2610 80 2421 2738 3055 2811 2877 85 2581 2903.5 3226 3030 3120 90 2740 3069 3398 3180 3186 95 2900 3234.5 3569 3210 3270 100 3060 3400 3740 3345 3345 Table 7. Test Data (Application Example 1) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 10 Application Note 1041 4000 Lower Limit Target Upper Limit Fan 1 Fan 2 Rotating Speed (RPM) 3500 3000 2500 2000 1500 1000 500 0 20 40 60 80 100 Input Duty (%) Figure 10. Curves of Rotating Speed (Application Example 1) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 11 Application Note 1041 4.2 Application Example 2 4.2.1 Requirement of Customer’s Target Product: (1) Rotating speed remains unchanged under the condition: input duty≤30% (2) When input duty linearly increases from 30% to 90%, the rotating speed linearly increases accordingly. (3) Rotating speed remains unchanged when input duty varies from 90% to 100%. 4.2.2 Customer’s Specification Data Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) 0 730 1110 1479 5 730 1110 1479 10 730 1110 1479 15 730 1110 1479 20 730 1110 1479 25 730 1110 1479 30 730 1110 1479 35 929 1306 1673 40 1128 1505 1867 45 1372 1701 2063 50 1525 1896 2255 55 1724 2092 2451 60 1922 2287 2642 65 2121 2483 2838 70 2319 2678 3030 75 2518 2874 3224 80 2717 3069 3418 85 2916 3265 3612 90 3114 3460 3806 95 3114 3460 3806 100 3114 3460 3806 Table 8. Customer’s Specification Data (Application Example 2) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 12 Application Note 1041 4000 Rotating Speed (RPM) 3500 Lower Limit Target Upper Limit 3000 2500 2000 1500 1000 500 0 20 40 60 80 100 Input Duty (%) Figure 11. Specification Curves of Rotating Speed (Application Example 2) 4.2.3 Recommended Application Circuit Application Example 2 (Slope K and Minimum/maximum Duty Adjustable) Figure 12. Recommended Application Circuit (R1=15kΩ, R2=5.125kΩ, R4=R5=220kΩ, R3, R6 Open) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 13 Application Note 1041 4.2.4 Test Data and Curve Figure Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 730 1110 1479 1182 5 730 1110 1479 1186 10 730 1110 1479 1194 15 730 1110 1479 1188 20 730 1110 1479 1224 25 730 1110 1479 1228 30 730 1110 1479 1272 35 929 1306 1673 1406 40 1128 1505 1867 1572 45 1372 1701 2063 1736 50 1525 1896 2255 1952 55 1724 2092 2451 2146 60 1922 2287 2642 2328 65 2121 2483 2838 2522 70 2319 2678 3030 2707 75 2518 2874 3224 2864 80 2717 3069 3418 3120 85 2916 3265 3612 3264 90 3114 3460 3806 3350 95 3114 3460 3806 3416 100 3114 3460 3806 3428 Table 9. Test Data (Application Example 2) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 14 Application Note 1041 4000 Rotating Speed (RPM) 3500 Lower Limit Target Upper Limit AM4962 3000 2500 2000 1500 1000 500 0 20 40 60 80 100 Input Duty (%) Figure 13. Curves of Rotating Speed (Application Example 2) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 15 Application Note 1041 4.3 Application Example 3 4.3.1 Requirement of Customer’s Target Product: (1) When input duty linearly increases from 0% to 100%, the rotating speed linearly rises accordingly. (2) Slope K=1. 4.3.2 Customer’s Specification Data and Curve Figure. Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) 0 0 0 0 5 0 200 400 10 200 400 600 15 400 600 800 20 600 800 1000 25 787.5 1000 1212.5 30 975 1200 1425 35 1162.5 1400 1637.5 40 1350 1600 1850 45 1537.5 1800 2062.5 50 1725 2000 2275 55 1912.5 2200 2487.5 60 2100 2400 2700 65 2287.5 2600 2912.5 70 2475 2800 3125 75 2662.5 3000 3337.5 80 2850 3200 3550 85 3037.5 3400 3762.5 90 3225 3600 3975 95 3412.5 3800 4187.5 100 3600 4000 4400 Table 10. Customer’s Specification Data (Application Example 3) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 16 Application Note 1041 4500 4000 Lower Limit Target Upper Limit Rotating Speed (RPM) 3500 3000 2500 2000 1500 1000 500 0 -500 0 20 40 60 80 100 Input Duty (%) Figure 14. Specification Curves of Rotating Speed (Application Example 3) 4.3.3 Recommended Application Circuit Application Example 3 (Slope K and Minimum/Maximum Duty Adjustable) Figure 15. Recommended Application Circuit (R1, R2, R4, R5, R6 open, R3=750kΩ, C1=1µF, C2=0.47µF, C3 open) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 17 Application Note 1041 4.3.4 Test Data and Curve Figure Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 0 0 0 0 5 0 200 400 150 10 200 400 600 360 15 400 600 800 600 20 600 800 1000 870 25 787.5 1000 1212.5 1080 30 975 1200 1425 1290 35 1162.5 1400 1637.5 1530 40 1350 1600 1850 1710 45 1537.5 1800 2062.5 1920 50 1725 2000 2275 2100 55 1912.5 2200 2487.5 2280 60 2100 2400 2700 2490 65 2287.5 2600 2912.5 2670 70 2475 2800 3125 2820 75 2662.5 3000 3337.5 3000 80 2850 3200 3550 3150 85 3037.5 3400 3762.5 3300 90 3225 3600 3975 3450 95 3412.5 3800 4187.5 3600 100 3600 4000 4400 3750 Table 11. Test Data (Application Example 3) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 18 Application Note 1041 4500 4000 Lower Limit Target Upper Limit AM4962 Rotating Speed (RPM) 3500 3000 2500 2000 1500 1000 500 0 -500 0 20 40 60 80 100 Input Duty (%) Figure 15. Curves of Rotating Speed (Application Example 3) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 19 Application Note 1041 4.4 Application Example 4 4.4.1 Requirement of Customer’s Target Product: Keep maximum speed regardless of the input duty (0% to 100%) 4.4.2 Customer’s Specification Data and Curve Figure. Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) 0 3014 3360 3706 5 3014 3360 3706 10 3114 3460 3806 15 3114 3460 3806 20 3114 3460 3806 25 3114 3460 3806 30 3114 3460 3806 35 3114 3460 3806 40 3114 3460 3806 45 3114 3460 3806 50 3114 3460 3806 55 3114 3460 3806 60 3114 3460 3806 65 3114 3460 3806 70 3114 3460 3806 75 3114 3460 3806 80 3114 3460 3806 85 3114 3460 3806 90 3114 3460 3806 95 3114 3460 3806 100 3114 3460 3806 Table 12. Customer’s Specification Data (Application Example 4) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 20 Application Note 1041 3800 Rotating Speed (RPM) 3600 3400 3200 3000 Lower Limit Target Upper Limit 2800 0 20 40 60 80 100 Input Duty (%) Figure 16. Specification Curves of Rotating Speed (Application Example 4) 4.4.3 Recommended Application Circuit Application 4 (Slope K and Minimum/Maximum Duty Adjustable) Figure 17. Recommended Application Circuit (R1, R2, R3, R5, R6 Open, R4 short) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 21 Application Note 1041 4.4.4 Test Data and Curve Figure Input Duty (%) Lower Limit (RPM) Target (RPM) Upper Limit (RPM) Rotating Speed (RPM) 0 3014 3360 3706 3410 5 3014 3360 3706 3358 10 3114 3460 3706 3450 15 3114 3460 3806 3390 20 3114 3460 3806 3420 25 3114 3460 3806 3460 30 3114 3460 3806 3380 35 3114 3460 3806 3350 40 3114 3460 3806 3345 45 3114 3460 3806 3390 50 3114 3460 3806 3348 55 3114 3460 3806 3370 60 3114 3460 3806 3390 65 3114 3460 3806 3348 70 3114 3460 3806 3400 75 3114 3460 3806 3390 80 3114 3460 3806 3408 85 3114 3460 3806 3429 90 3114 3460 3806 3360 95 3114 3460 3806 3390 100 3114 3460 3806 3408 Table 13. Test Data (Application Example 4) Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 22 Application Note 1041 3800 Rotating Speed (RPM) 3600 3400 3200 3000 Lower Limit Target Upper Limit AM4962 2800 0 20 40 60 80 100 Input Duty (%) Figure 18. Curves of Rotating Speed (Application Example 4) Note 2: 1) D2 and D3 are recommended to be used when the current in coil L1 is higher than 300mA in Figure 2, Figure 9, Figure 12, Figure 15. 2) VCC=12V, unless otherwise specified. Dec. 2009 Rev. 1. 0 BCD Semiconductor Manufacturing Limited 23