Application Note ACT5028 Resolver-To-Digital Converter (RDC) Evaluation Board Application Note AN5028-1 Rev A Scope: This application note is to aid in the support of testing and evaluation of the ACT5028 Resolver to Digital (RDC) Converter on the ACT5028 Evaluation board developed by Aeroflex. The Resolver inputs can be from an actual Resolver or a simulator as noted in Support Equipment below. Support Documentation: a) ACT5028 Product Data Sheet b) 5028-411 Schematic of Evaluation Board c) 5028-480 Evaluation Board Assembly d) SW5028-2 Software Program to determine RDC bandwidth component values Support Equipment Required: a) +5 Volt Power Supply capable of .25amps b) +5 to +3 Volt Power Supply if required for VLI/O c) Sine Wave Generator capable of 20 KHz @ 3 Volts RMS d) North Atlantic Industry Synchro / Resolver Simulator Model 5330 or equivalent e) Digital Multi Meter (Measure voltage, current, resistance, & capacitance) f) Digital Oscilloscope Connector Inputs: J1 J2 J3 K1 +SIN -SIN +COS -COS +REF -REF +5V VLI/O GND Used for Auto Test (Resolver Signals) Used for Auto Test (Control Signals) Used for Auto Test (Data Bus) Used for Auto Test (Power Relay) +SIN input signal from Resolver -SIN input signal from Resolver +COS input signal from Resolver -COS input signal from Resolver +REF input signal from sine wave generator -REF input signal from sine wave generator System Power Supply Alternate Digital Interface Power (5-3.3Volts) System Ground Controls: S1 S2 S3 S4 S5 S6 S7 S8 S9-24 Power on switch (ON/OFF) for +5 V & VLI/O inputs DATALOAD; Loads the contents of the Data Bus into the RDC Converter *Logic 0 No Load *Note: Rev B Silicon has a reverse polarity *Logic 1 Load Data VLI/O; Digital Logic Interface voltage Logic 0 selects +5 Volts Logic 1 selects VLI/O input SC1; Mode Select SC1/S4 SC2/S5 SC2; 0 0 10 Bit Mode 0 1 12 Bit Mode 1 0 14 Bit Mode 1 1 16 Bit Mode INH; Logic 0 Inhibits Data Bus from changing Logic 1 Enables Data Bus changes ENABLE; Logic 0 Enables Data Bus as an Output Port Logic 1 Disables Data Bus output, HiZ State LED POWER (ON/OFF) Data Bus; Note care should be taken when driving the Data Bus, ENABLE should be at Logic 1. Logic 0 selects a low logic level Logic 1 selects a Hi logic level Center position provides a HiZ state from the switch Application Note AN5028-1 2 Rev A LEDs: Power On LED indicates that +5 Volts is turned on by S1. Bit1-Bit16 Indicates the status of the corresponding Data bit on the Bus. Electronic Components TBD: Resolver Characteristics R7-R10 R27 C5-C8 Resistor Values TBD, 1/8w, 1% Resistor Values TBD, 1/8w, 1% Ceramic Capacitor TBD, 25 Volt, 5% Input Conditioning R1-R4 R13-R20 C9-C10 Resistor Values TBD, 1/8w, 1% Resistor Values TBD, 1/8w, 1% Ceramic Capacitor TBD, 25 Volt, 5% Evaluation Board Setup: Determine System Characteristics: All of the loop components (resistors & capacitors) are calculated for you in a convenient program, simply input the following information in the program. The reference designations in the program do not match the Evaluation Board, they reference the ACT5028 Product Data Sheet. ACT5028 Evaluation Bd R10 same as R8 = R27 same as R7 = R9 same as C6 = C8 same as C5 = C7 same as Product Data Sheet R3 R1 R2 C2 C3 Program Inputs: a) Resolution b) Maximum Tracking Rate c) Closed Loop Bandwidth BWCL d) Carrier Frequency e) SIN & COS input levels Resolution (Also configure SC1 & SC2 Switches on PCB) Select 10 for .35° (10 Bit Mode) Select 12 for .09 ° (12 Bit Mode) Select 14 for .022° (14 Bit Mode) Select 16 for .0055° (16 Bit Mode) Maximum Tracking Rate 0 to 1024 RPS for 10 Bit Mode 0 to 256 RPS for 12 Bit Mode 0 to 64 RPS for 14 Bit Mode 0 to 16 RPS for 16 Bit Mode Closed Loop Bandwidth Typically > 10x Maximum Tracking Rate Carrier Frequency (Supplied by user) Range 45 to 30KHZ Must be > 4 x BWCL in 10 Bit Mode Must be > 8 x BWCL in 12 Bit Mode Must be > 12 x BWCL in 14 Bit Mode Must be > 16 x BWCL in 16 Bit Mode SIN & COS Input (Supplied by user) 1 to 1.5 Vrms Application Note AN5028-1 3 Rev A Input Signal Conditioning: The first decision is to select Single Ended or Differential input conditioning, Figure 1 shows the circuit components that must be selected. To maintain the best accuracy resistor tolerance and matching will be important. The input amplitude is not as important (staying within recommended input range) as maintaining matched amplitudes on the SIN and COS and when using differential inputs, symmetry should be maintained. Note the resistor reference designations in Figure 1 are grouped by A, B, C and D. Each group will have the same value and should be matched as close as possible. If no attenuation is required in the SIN / COS inputs, resistor group A is replaced with zero ohm jumper wires. If no attenuation is required for the Reference input, resistor group C would be replaced with zero ohm jumper wires. Reference Input Conditioning: Most Resolvers have a LEADING input to output phase shift. A simple C-R leading phase shift network from the Resolver reference to the RDC’s reference input will provide the compensating phase shift required to bring the signals in phase. If the Resolver has a LAGGING input to output phase shift an R-C lagging phase shift network (low pass network) would be required. The resistor group D would need a capacitor in parallel and if no attenuation is required the resistor can be omitted. The Reference Phase Lead can be calculated by the following formula; Phase angle = ArcTan _________1_______ 6.28 x (RC + RD) x C FREF FREF is the reference frequency for the Reference signal being applied to the RDC Reference input. When selecting component it would be easiest to select the capacitor values C9 and C10 (Ceramic Capacitors) that should be matched as close as possible. After first selecting the capacitor use the following formula to select the resistors. RC + RD = ________________1_________________ (Tan (Phase Angle)) x FREF x 6.28 x C Note the C-R phase lead circuit on the input to the Demodulator (pins 15 & 16) should be considered when calculating the total system phase compensation. This phase lead adds to the phase lead developed by the Resolver. Application Note AN5028-1 4 Rev A RA 1 RA 1 + SIN PIN 22 + SIN RB 3 VCC /2 VCC /2 - SIN RA 15 + COS RA 2 0 Ohms - SIN PIN 21 - SIN + COS PIN 25 +COS VCC /2 - COS C10 RC 14 + REF - COS + REF PIN 12 + REF C 10 VCC /2 RC 16 +REF PIN 12 RD 19 RD 20 0 Ohms C9 - REF PIN 11 - REF - COS PIN 24 RC 14 RD 20 C9 RB 17 RA 13 0 Ohms - COS PIN 24 RD 19 VCC /2 +COS PIN 25 RB 18 0 Ohms RB 18 RA 13 - SIN PIN 21 RA 15 RB 17 VCC /2 RB 3 RB 4 0 Ohms RB 4 RA 2 + SIN PIN 22 +SIN - REF Differential Input Configuration RC 16 0 Ohms - REF PIN 11 Single-Ended Input Configuration Figure 1 – Input Signal Conditioning PLAINVIEW, NEW YORK Toll Free: 800-THE-1553 Fax: 516-694-6715 INTERNATIONAL Tel: 805-778-9229 Fax: 805-778-1980 NORTHEAST Tel: 603-888-3975 Fax: 603-888-4585 SE AND MID-ATLANTIC Tel: 321-951-4164 Fax: 321-951-4254 WEST COAST Tel: 949-362-2260 Fax: 949-362-2266 CENTRAL Tel: 719-594-8017 Fax: 719-594-8468 www.aeroflex.com [email protected] As we are always seeking to improve our products, the information in this document gives only a general indication of the product capacity, performance and suitability, none of which shall form part of any contract. We reserve the right to make design changes without notice. All trademarks are acknowledged. Parent company Aeroflex, Inc. ©Aeroflex 2003. Application Note AN5028-1 Our passion for performance is defined by three attributes represented by these three icons: solution-minded, performance-driven and customer-focused 5 Rev A