LB1939T 2 Channel H Bridge Constant Voltage/Constant Current Driver www.onsemi.com Overview Package Dimensions The LB1939T is a two-phase excitation bipolar stepping motor driver that features low voltage operation, a low saturation voltage, and low power consumption. It supports constant voltage and constant current drive, can control two iris motors, and is optimal for shutter, iris, and AF drive in 3 V battery operated still digital cameras and other battery operated equipment. unit: mm 3246-TSSOP20 [LB1939T] 20 0.5 6.5 4.4 6.4 11 Features 1 0.22 10 0.15 0.08 0.65 (0.33) (1.0) 1.2max • Low-voltage drive — Dual power supply operation: VS = 1.6 to 7.5 V, VDD = 1.9 to 6.5 V — Single power supply operation: VS = VDD = 1.9 to 7.5 V • Low saturation voltage output: Vosat = 0.3 V at IO = 200 mA • Supports constant voltage and constant current drive • Built-in reference voltage circuit (Vref = 0.9 V) • Miniature, thin form package (Thickness t = 1.1 mm) TSSOP20 Specifications Absolute Maximum Ratings at Ta = 25°C Ratings Unit Maximum supply voltage Parameter VBmax VS1, VS2, VDD –0.3 to +10.5 V Applied output voltage VOUT OUT1, 2, 3, 4 –0.3 to +10.5 Maximum output current: OUT1, 2, 3, and 4 IOmax t 10 ms 400 ENA, IN, VC 10.5 V 0.8 W Applied input voltage Allowable power dissipation Symbol VIN Pdmax Conditions When mounted on a printed circuit board* V mA Operating temperature Topr –20 to +85 °C Storage temperature Tstg –55 to +150 °C Note: Circuit board: 114.3 76.1 1.6 mm3 glass epoxy board © Semiconductor Components Industries, LLC, 2013 December 2013 - Rev. 0 1 Publication Order Number : LB1939T/D LB1939T Allowable Operating Conditions at Ta = 25°C Parameter Symbol Conditions Ratings min typ Unit max Operation guaranteed voltage range 1 VOPR1 VDD system, VS = 2.0 V 1.9 6.5 Operation guaranteed voltage range 2 VOPR2 VS system, VDD = 5.0 V 1.6 7.5 V V Input low-level threshold voltage VIL ENA1, ENA2, IN1, IN2 –0.3 +1.0 V Input high-level threshold voltage VIH ENA1, ENA2, IN1, IN2 2.0 6.0 V Electrical Characteristics at Ta = 25°C, VS = 3.0 V, VDD = 5.0 V Parameter Symbol Standby mode current drain Conditions Ratings min typ Unit max ISTB VS = VDD = 6.5 V VREF output voltage VREF IOL = 0 to 1 mA SVDD output voltage VSVDD IOL = 10 mA OUT pin output saturation voltage 1 (Saturation control mode) Vosat1 VDD = 5.0 V, VC = SVDD, VS = 2.0 V IO = 200 mA (PNP transistor side) 0.20 0.30 V OUT pin output saturation voltage 2 (Saturation control mode) Vosat2 VDD = 5.0 V, VC = SVDD, VS = 2.0 V IO = 200 mA (NPN transistor side) 0.10 0.15 V OUT pin output voltage 1 (Constant voltage control mode) VOUT1 VDD = 6.0 V, VC = 1.5 V, VS = 3.5 V IO = 200 mA (PNP transistor side) 2.8 2.9 3.0 V OUT pin output voltage 2 (Constant voltage control mode) VOUT2 VDD = 6.0 V, VC = VREF, VS = 2.0 V IO = 200 mA (PNP transistor side) 1.65 1.75 1.85 V OUT pin output current 1 (Constant current control mode) IOUT1 VDD = 6.0 V, VC = 0.9 V, VS = 3.5 V RL = 5 Ω (between OUT and OUT), RFB = 1 Ω 197 210 223 mA OUT pin output current 2 (Constant current control mode) IOUT2 VDD = 6.0 V, VC = VREF, VS = 2.0 V RL = 5 Ω (between OUT and OUT), RFB = 1 Ω 189 210 231 mA 0.1 1.0 µA 0.85 0.9 0.95 V 4.7 4.8 [Regulator Output Circuit] V [H Bridge Output Circuit] VS system operating current drain 1 IS1 VC = SVDD 4 7 mA VS system operating current drain 2 IS2 VC = VREF 1.5 3 mA VDD system operating current drain 1 IDD1 VC = SVDD ENA1 = 2 V 4 7 mA VDD system operating current drain 2 IDD2 VC = VREF ENA1 = 2 V 4 7 mA VC input voltage range VC 0.1 VC input current IVC VDD = 6.0 V, VS = 2.0 V, VC = 5.0 V IIH VIH = 5.5 V IIL VIL = GND 0 7 V 50 100 µA 70 100 µA 0 µA [Control Input Circuit] Control pin maximum input current –1 Allowable power dissipation, Pdmax — W Pd max — Ta 1 Mounted on a 114.3 × 76.1 × 1.6 mm glass-epoxy printed circuit board 0.8 0.6 0.4 0.2 0 –20 0 20 40 60 80 100 Ambient temperature, Ta — °C www.onsemi.com 2 LB1939T Truth Table Input Output ENA IN 1 2 L L H H 1 OUT 2 3 SVDD 4 Mode 1 2 H L H on Channel 1: reverse L H L on Channel 1: forward Standby mode (zero current drain) H L H on Channel 2: reverse L H L on Channel 2: forward Blank entries indicate “don’t care” states. Blank entries indicate off states. Pin Assignment VC1 1 20 VS1 S-GND 2 19 SVDD VC2 3 18 VDD Vref 4 17 OUT1 ENA1 5 16 RFG1 LB1939T ENA2 6 15 OUT2 IN1 7 14 OUT3 IN2 8 13 RFG2 FC1 9 12 OUT4 11 VS2 FC2 10 Top view www.onsemi.com 3 S--GND -- RFG1 + 65kW -- VDD-SW VREF SVDD OUT4 RFG2 -- + FC2 VS2 ENA1 ENA2 IN1 IN2 -- -- + OUT3 + 65kW -- Reference voltage logic circuit VDD 80kW + FC1 OUT2 80kW + OUT1 65kW 70kW 20kW VS1 80kW 4 65kW www.onsemi.com 80kW VC2 70k 20k VC1 LB1939T Block Diagram LB1939T Application Circuit Example 1 VS2 VDD VS1 ENA1 ENA2 CPU OUT1 OUT2 IN1 LB1939T IN2 OUT3 OUT4 S-GND SVDD Vref VC1 VC2 RFG1 RFG2 Constant voltage control mode: OUT outputs a 1.75 V, which is Vref (0.9 V) × 1.95. * : FC1 and FC2 are left open. Application Circuit Example 2 VS2 VDD VS1 ENA1 OUT1 ENA2 CPU OUT2 IN1 LB1939T IN2 OUT3 OUT4 S-GND FC1 SVDD FC2 Vref VC1 VC2 RFG1 RFG2 RFB RFB Constant current control mode: The RFG voltage is controlled so that Vref/4.5 = 0.2 V. Therefore, when RfB is 1 Ω, the circuit operates in constant current drive with Icoil = 0.2 V/1 Ω = 200 mA. *: There are no magnitude constraints on the inputs (ENA, IN) and the supply voltages (VDD, VS). For example, the IC can be operated at VIN = 5 V, VDD = 3 V, and VS = 2 V. www.onsemi.com 5 LB1939T Application Circuit Example 3 VS2 VDD VS1 ENA1 ENA2 OUT1 OUT2 IN1 CPU LB1939T IN2 OUT3 OUT4 S-GND FC2 SVDD 6 kΩ VC1 Vref VC2 RFG1 RFG2 3 kΩ Channel 1 operates in constant voltage control mode: OUT outputs VDD × 3K/(3K + 6K) × 1.95 Channel 2 operates in constant current control mode: The RFG voltage is controlled so that Vref/4.5 = 0.2 V. * : FC1 is left open. Notes on Constant Current Control Settings The LB1939T constant current control circuit has the structure shown in the figure at the right. The voltage input to the VC pin is resistor divided internally (by 70 kΩ and 20 kΩ resistors) to 1/4.5 and input to the plus (+) input of the constant current control amplifier as reference. The minus (–) input of this constant current control amplifier is connected, through the wire bond resistor Rb (= 0.1 Ω), to the RFG pin. The constant current control circuit operates by comparing the voltage generated by the external current detection resistor connected to the RFG pin and the reference voltage mentioned above. VS VC Constant current control amplifier 70 kΩ OUT1 VA RL 20 kΩ Note that the voltage at VA will be that given by the following formula since the bias current Ib (= 1.5 µA) flows from the constant current control amplifier plus (+) input during constant current control operation. VA = VC/4.5 + Ib × 20 kΩ = VC/4.5 + 0.03 Ib = 1.5 µA Iout OUT2 Pad Rb = 0.1 Ω RFG RFB A13864 Therefore, the logical expression for setting the constant current Iout is as follows. Iout = VA/(RFB + Rb) = (VC/4.5 + 0.03) / (RFB + Rb) ......(1) www.onsemi.com 6 LB1939T Constant Current Control Usage Notes This IC supports both constant current control and constant voltage control modes. However, since both of these control circuits operate at all times, certain of the limitations imposed by the constant voltage control circuit apply may when using constant current control. For example, if constant current control is used with the application circuit example 2, if VC = 0.9 V (= Vref) and RFB = 1 Ω, then the output current can be calculated as follows from (1) on the previous page. Iout = (0.9/4.5 + 0.03) / (1 + 0.1) = 0.23/1.1 0.209A Here, if the value driven load resistance RL is r, since the RFG pin voltage is 0.23 V and the npn transistor output saturation voltage is 0.1 V (typical), the pnp transistor output pin voltage can be calculated as follows. Vout = (RFG pin voltage) + (npn transistor output saturation voltage) + (voltage across the load terminals) = 0.23 + 0.1 + 0.209 r = 0.3 + 0.209r At the same time, however, this IC’s internal constant voltage control circuit controls the output voltage as follows. Vout' = VC 1.95 1.75 V Therefore, it will not be possible to use the constant current control mode if the value of r is set so that Vout is greater than Vout'. That is, the condition 0.33 + 0.209r > 1.75 implies that r > 6.79 This means that constant current control can be used when the value of the load resistance used is strictly less than 6.79 . ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC) or its subsidiaries in the United States and/or other countries. SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf . SCILLC reserves the right to make changes without further notice to any products herein. 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