NJU39612 MICROSTEPPING MOTOR CONTROLLER WITH DUAL DAC n GENERAL DESCRIPTION n PACKAGE OUTLINE NJU39612 is a dual 7-bit+sign Digital-to-Analog Converter (DAC) developed to be used in micro stepping applications together with the dual stepper motor driver. The NJU39612 has a set of input registers connected to an 8-bit data port for easy interfacing directly to a microprocessor. Two registers are used to store the data for each seven-bit DAC, the eighth bit being a sign bit (sign/magnitude coding). NJU39612E2(SOP20) n FEATURES Analog control voltages from 3V down to 0.0V High-speed microprocessor interface Full -scale error 1 LSB Fast conversion speed 3 m s Matches the dual stepper motor drivers Package SOP20 JEDEC 300 mil n BLOCK DIAGRAM V V DD Ref NJU39612 WR Sign 1 DA- Data 1 E1 E CS C D DA 1 D / A R E2 A0 DA DA- Data 2 2 D / A E C D7 - D0 D R Sign POR 2 R RESET V ss Figure 1. Block DiagramNJU39612 n PIN CONFIGURATION V 1 20 Reset ref DA 2 19 DA 2 1 Sign Sign 3 18 2 1 17 V VDD 4 ss CS WR 5 16 NJU39612E2 15 D7 6 NC D6 7 14 A0 D5 8 13 D0 D1 D4 12 9 D3 10 11 D2 Figure 2. Pin configuration n PIN DESCRIPTION Refer to figure 2. SOP Symbol Description 1V Voltage reference supply pin, 2.5 V nominal (3.0 V maximum) Ref 2DA Digital-to-Analog 1, voltage output. Output between 0.0 V and V - 1 LSB. 1 ref 3 Sign Sign 1, TTL/CMOS level. To be connected directly to NJM377x phase input. Databit D7 is transfered non 1 inverted from NJU39612 data input. 4V Voltage Drain-Drain, logic supply voltage. Normally +5 V. DD 5 WR Write, TTL/CMOS level, input for writing to internal registers. Data is clocked into flip flops on positive edge. 6 D7 Data 7, TTL/CMOS level, input to set data bit 7 in data word. 7 D6 Data 6, TTL/CMOS level, input to set data bit 6 in data word. 8 D5 Data 5, TTL/CMOS level, input to set data bit 5 in data word. 9 D4 Data 4, TTL/CMOS level, input to set data bit 4 in data word. 10 D3 Data 3, TTL/CMOS level, input to set data bit 3 in data word. 11 D2 Data 2, TTL/CMOS level, input to set data bit 2 in data word. 12 D1 Data 1, TTL/CMOS level, input to set data bit 1 in data word. 13 D0 Data 0, TTL/CMOS level, input to set data bit 0 in data word. 14 A0 Address 0, TTL/CMOS level, input to select data transfer, A0 selects between cannel 1 (A0 = LOW) and channel 2 (A0 = HIGH). 15 NC Not connected 16 CS Chip Select, TTL/CMOS level, input to select chip and activate data transfer from data inputs. LOW level = chip is selected. 17 V Voltage Source-Source. Ground pin, 0 V reference for all signals and measurements unless otherwise SS noted. 18 Sign Sign 2. TTL/CMOS level. To be connected directly to NJM377x phase input. Data bit D7 is transfered 2 non-inverted from NJU39612 data input. 19 DA Digital-to-Analog 2, voltage output. Output between 0.0 V and V - 1 LSB. 2 ref 20 Reset Reset, digital input resetting internal registers. HIGH level = Reset, V 3.5 V = HIGH level. Pulled low Res internally.