TS3003 Demo Board A 1.55V to 5.25V, 1.9µA, 9kHz to 300kHz Silicon Timer FEATURES DESCRIPTION The TS3003 is a single-supply, second-generation Touchstone Semi oscillator/timer fully specified to operate at a supply voltage range of 1.55V to 5.25V while consuming less than 2.4μA(max) supply current. Requiring only a resistor to set the base output frequency (or output period) at 25kHz (or 40µs) with a 50% duty cycle, the TS3003 timer/oscillator is compact, easy-to-use, and versatile. Optimized for ultra-long life, low frequency, battery-powered/portable applications, TS3003 joins the TS3001, TS3002, TS3004, and TS3006 in Touchstone’s CMOS timer family in its “NanoWatt Analog™” series of high-performance analog integrated circuits. 5V Supply Voltage FOUT/PWMOUT Output Period: 40µs(25kHz) o RSET = 4.32MΩ PWMOUT Output Duty Cycle: o 75% for FDIV2:0 = 000 o CPWM = 100pF PWMOUT Duty Cycle Reduction o 1MΩ Potentiometer Fully Assembled and Tested 2in x 2in 2-layer circuit board COMPONENT LIST DESIGNATION QTY DESCRIPTION C1 1 C2 1 R2 R1 PWM_ADJ U1 VDD,F_OUT, PWM_OUT J1 1 1 1 1 3 100pF ±10% capacitor (0805) 4.7µF ±10% capacitor (0805) 10MΩ ± 1% (0805) 4.32MΩ ± 1% (0805) 1MΩ Potentiometer TS3003 Test points 1 Jumper The TS3003 requires only an RSET = 4.32MΩ resistor to set the FOUT/PWMOUT output period to 40µs(25kHz). With an on-board 100pF CPWM capacitor, the duty cycle of PWMOUT is set at approximately 75%. Further reduction of the duty cycle is available with an on-board 1MΩ potentiometer. The complete circuit is designed at a supply voltage of 5V. The TS3003 is fully specified over the -40°C to +85°C temperature range and is available in a low-profile, 10-pin 3x3mm TDFN package with an exposed back-side paddle. Product datasheet and additional documentation can be found on the factory web site at www.touchstonesemi.com. ORDERING INFORMATION Order Number TS3003DB Description TS3003 Demo Board Figure 1. TS3003 Demo Board Circuit Page 1 © 2013 Touchstone Semiconductor, Inc. All rights reserved. TS3003 Demo Board DESCRIPTION The TS3003 requires only an RSET = 4.32MΩ resistor to set the FOUT/PWMOUT output period to 40µs(25kHz). With an on-board 100pF CPWM capacitor, the duty cycle of PWMOUT is set at approximately 75%. Further reduction of the duty cycle is available with an on-board 1MΩ potentiometer. The complete circuit is designed at a supply voltage of 5V and it is shown in Figure 1. The TS3003 is a user-programmable oscillator where the period of the square wave at its FOUT terminal is generated by an external resistor connected to the RSET pin. The output period is given by: O T( ) 1 08 11 S T Equation 1. FOUT Frequency Calculation With RSET = 4.32MΩ, the FOUT period is approximately 40µs (25kHz) with a 50% duty cycle. As design aids, Tables 1 lists TS3003’s typical O T frequency for various standard values for RSET. RSET (MΩ) FOUT (kHz) 0.360 300 1 108 2.49 43.37 4.32 25 6.81 15.86 9.76 11.07 12 9 Table 1: FOUT vs RSET The TS3003 also provides a separate PWM output signal at its PWMOUT terminal that is anti-phase with respect to FOUT. To adjust the pulse width of the PWMOUT output, a single capacitor can be placed at the CPWM pin. To determine the capacitance needed for a desired pulse width, the following equation is to be used: CPWM( ) Pulse Width(s) CPWM 00m CPWM Equation 2. CPWM Capacitor Calculation where ICPWM and VCPWM is the current supplied and voltage applied to the CPWM capacitor, respectively. TS3003DB r1p0 The pulse width is determined based on the period of FOUT and should never be greater than the period at FOUT. Make sure the PWM_CNTRL pin is set to at least 400mV when calculating the pulse width of PWMOUT. Note VCPWM is approximately 300mV, which is the RSET voltage. Also note that ICPWM is approximately 1µA. QUICK START PROCEDURE Required Equipment TS3003 Demo Board DC Power Supply Oscilloscope equivalent Two 10X, 15p //10MΩ oscilloscope probes Potentiometer screwdriver Model Agilent DSO1014A or To evaluate the TS3003 silicon timer, the following steps are to be performed: 1) Before connecting the DC power supply to the demo board, turn on the power supply, set the DC voltage to 5V, and then turn it off. 2) Connect the DC power supply positive terminal to the test point labeled VDD. Connect the negative terminal of the DC power supply to the test point labeled GND. 3) To monitor the FOUT output signal, connect the signal terminal of an oscilloscope probe to the test point labeled FOUT and the ground terminal to the test point labeled GND. 4) To monitor the PWMOUT output signal, connect the signal terminal of a second oscilloscope probe to the test point labeled PWM_OUT and the ground terminal to the test point labeled GND. 5) Select two channels on the oscilloscope and set the vertical voltage scale and the vertical position on each channel to 2V/DIV and 0V, respectively. Set the horizontal time scale to 5µs/DIV. The coupling should be DC coupling. Turn on the power supply. The supply current will vary depending on the load on the output. Given the default set-up on the board, the FOUT/PWMOUT output period is approximately 40µs. The PWMOUT duty cycle is set to approximately 75%. With an output load of Page 2 RTFDS TS3003 Demo Board 15pF on both FOUT and PWMOUT outputs due to the oscilloscope probes, the supply current should be less than 8µA. TS3003DB r1p0 6) If further reduction of the duty cycle of the PWMOUT output is desired, turn the potentiometer clockwise. If jumper J1 is removed, the PWM_CNTRL pin is tied to VDD and the potentiometer will not change the PWMOUT output duty cycle. Page 3 RTFDS TS3003 Demo Board Period vs RSET 120 PERIOD - µs 100 80 60 40 20 0 0 2 4 6 8 10 12 RSET - MΩ Figure 2. FOUT/PWMOUT Period vs RSET Figure 3. Top Layer View #1 Figure 4. Top Layer View #2 Figure 5. Bottom Layer (GND) #2 Figure 6. Bottom Layer (GND) #2 Page 4 Touchstone Semiconductor, Inc. 630 Alder Drive, Milpitas, CA 95035 +1 (408) 215 - 1220 ▪ www.touchstonesemi.com TS3003DB r1p0 RTFDS