Rev 0; 3/05 Voltage Sample and Infinite Hold The DS4303 is a nonvolatile (NV) sample and infinitehold adjustable voltage reference. The reference voltage is programmed in-circuit during factory calibration/ programming. Programming the reference voltage, VOUT, is as simple as applying the desired voltage on VIN and toggling the adjust pin (ADJ) to lock the VOUT voltage level indefinitely, even if the device is power cycled. The DS4303 replaces current cumbersome factory adjustment arrangements with a low-cost solution that can be adjusted using automated techniques. In addition, the DS4303 has the ability to be readjusted after the unit has been fully assembled and tested. This results in a much more flexible manufacturing arrangement, lower inventory costs, and a quicker time-to-market. Features ♦ Precise Electronically Adjustable Voltage Reference ♦ Enables Automated Factory Trimming of Devices Needing Voltage Adjustment ♦ Can be Adjusted to Within ±1mV ♦ Wide Adjustable Output Voltage Range Within 300mV of the Supply Rails ♦ Low Temperature Coefficient ♦ ±1mA of Output-Current Drive ♦ NV Memory Stores the Voltage Indefinitely ♦ Output Short-Circuit Protection Applications ♦ Low Cost Power-Supply Calibration ♦ Low Power Consumption Threshold Setting ♦ 2.4V to 3.6V Single-Supply Operation Offset Nulling ♦ Small 5-Lead SOT23 Package Bias Adjusting Power Amps Ordering Information Pressure Bridges Factory-Calibrated Equipment PART TEMP RANGE PINPACKAGE DS4303R/T&R -40°C to +85°C SOT23-5 4303 DS4303R+T&R -40°C to +85°C +Denotes lead-free package. SOT23-5 4303+ Pin Configuration Typical Operating Circuit EXISTING SOLUTION SOT MARK TOP VIEW DS4303 SOLUTION VCC REFERENCE VOLTAGE SHUNT VOLTAGE REFERENCE VCC ADJ 1 GND 2 VIN 3 5 VCC 4 VOUT DS4303 VOUT REFERENCE VOLTAGE DS4303 GND HAND SELECTED 0.1% RESISTOR OR MECHANICAL POT VIN ADJ ACCESS FOR AUTOMATED ALIGNMENT SOT23 ______________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 DS4303 General Description DS4303 Voltage Sample and Infinite Hold ABSOLUTE MAXIMUM RATINGS Voltage on VCC Relative to GND ...........................-0.5V to +6.0V Voltage on VIN, ADJ, and VOUT Relative to GND ...-0.5V to (VCC + 0.5V), not to exceed +6.0V Operating Temperature Range ...........................-40°C to +85°C EEPROM Programming Adjust Temperature..........0°C to +70°C VOUT to GND Short-Circuit Duration .........................Continuous Storage Temperature Range .............................-55°C to +125°C Soldering Temperature ...See IPC/JEDEC J-STD-020 Specification Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS (TA = -40°C to +85°C) PARAMETER SYMBOL Supply Voltage VCC VIN Voltage Range CONDITIONS (Note 1) MIN TYP MAX UNITS 2.4 3.6 V VIN 0.3 VCC - 0.3 V ADJ Logic 0 VIL -0.3 0.3 x VCC VOUT Current VOUTI -1 VOUT Load VOUTL V +1 mA 100 pF TYP MAX UNITS 1.1 1.6 mA ELECTRICAL CHARACTERISTICS (VCC = +2.4 to +3.6V, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER Supply Current SYMBOL ICC CONDITIONS MIN VIN, ADJ and VOUT = open circuit VIN Resistance RPD 95 ADJ Pullup Resistance RPU 18 kΩ kΩ VOUT Voltage Range VOUTR (Note 1) 0.3 VOUT Tracking Accuracy VOUTTA (Note 2) ±20 mV VOUT Quantization VOUTQ (Note 3) ±1 mV -40°C to +85°C, VOUT = 0.4V VOUT Temperature Coefficient VOUT Line Regulation VOUTTC VCC - 0.3 ±104 µV/°C -40°C to +25°C, VOUT = 3.0V -5 +28 +62 +25°C to +85°C, VOUT = 3.0V -31 -13 +6 VOUTLN -4.0 V ppm/°C +1.0 mV/V 5.5 mV/mA VOUT Load Regulation VOUTLD -1mA ≤ VOUTI ≤ +1mA Long-Term Stability VOUTLTS 1000 hours at +25°C TBD ppm en1 0.1Hz ≤ ƒ ≤ 10Hz 200 µVP-P en2 10Hz ≤ ƒ ≤ 1kHz 26 µVRMS ƒ= 200kHz 21 tST (Note 4) 11 15 ms/V EEPROM Programming Time tW (Note 5) 9 12 ms Turn-On Time tON VIN and ADJ = open circuit (Note 6) 10 µs ADJ Toggle Low Time tADJ VOUT Noise VOUT PSRR VOUT Self-Adjust Settling Time VOUT Factory Trimmed Value 2 VOUTPSRR VOUT FT 100 +25°C, VCC = 3.3V (Note 7) _____________________________________________________________________ dB ns 1200 mV Voltage Sample and Infinite Hold (VCC = +2.4V to 3.6V, unless otherwise noted.) PARAMETER SYMBOL Programming Cycles Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: CONDITIONS MIN +70°C (Note 8) TYP MAX UNITS 50,000 Cycles All voltages referenced to ground. Tracking accuracy is defined as VOUT - VIN after the DS4303 has completed self-adjustment. Quantization refers to the size of the voltage steps used to track the input signal. Settling time is the maximum amount of time VOUT requires to self-adjust. The settling time is determined by the following formula: ∆VOUT x tST. EEPROM programming time is the hold time required after the DS4303 has completed self-adjustment before VIN or VCC can be removed or before ADJ can be toggled low once again. Turn-on time is defined as the time required for VOUT to reach its specified accuracy after the required supply voltage is applied. VOUT not loaded. Guaranteed by design. Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) VCC = 3.3V 1.41 1.20 VCC = 3.0V 1.10 VCC = 2.4V VCC = 3.6V 1.39 1.37 1.35 1.33 VCC = 3.3V 1.31 IL = 0mA 1.27 ADJ = VCC 1.00 IL = 0mA -15 10 35 TEMPERATURE (°C) 60 85 TA = +85°C 1.30 TA = +25°C 1.25 TA = -40°C 1.20 1.15 1.05 ADJ = VCC 1.25 -40 1.35 1.10 1.29 1.05 1.40 DS4303 toc03 1.43 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 1.25 ACTIVE SUPPLY CURRENT vs. SUPPLY VOLTAGE DS4303 toc02 VCC = 3.6V 1.15 1.45 DS4303 toc01 1.30 ACTIVE SUPPLY CURRENT vs. TEMPERATURE (VOUT = 3.0V) SUPPLY CURRENT (mA) ACTIVE SUPPLY CURRENT vs. TEMPERATURE (VOUT = 0.3V) IL = 0mA 1.00 -40 -15 10 35 TEMPERATURE (°C) 60 85 2.4 2.6 2.8 3.0 3.2 3.4 3.6 SUPPLY VOLTAGE (V) _____________________________________________________________________ 3 DS4303 NONVOLATILE MEMORY CHARACTERISTICS Typical Operating Characteristics (continued) (VCC = 3.3V, TA = +25°C, unless otherwise noted.) LOAD REGULATION (VOUT = 3.0V) 2 1 TA = -40°C -1 -2 TA = +85°C -3 -5 0 TA = +85°C -1 -2 VCC = 3.6V -0.5 0 0.5 TA = -40°C -1500 TA = +25°C -2000 TA = +85°C -2500 -0.5 0 0.5 1.0 2.4 2.6 2.8 3.0 3.2 3.4 LOAD CURRENT (mA) LOAD CURRENT (mA) SUPPLY VOLTAGE (V) LINE REGULATION (VOUT = 3.0V) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (VCC = 3.6V) DS4303 OUTPUT NOISE (0.1Hz TO 10Hz) -50 VOUT = 0.3 V, VCC-AC = 300mV 45 3.6 300 DS4303 toc08 50 DS4303 toc07 0 200 -100 40 -200 TA = +25°C -250 100 VOUT (µV) PSRR (dB) TA = -40°C -150 35 30 -300 25 IL = 0mA -200 VCC = 3.6V -400 20 3.35 3.40 3.45 3.50 3.55 10 3.60 VOUT = 3.0V -300 1,000 100 0 1 2 FREQUENCY (kHz) TIME (s) DS4303 OUTPUT NOISE (10Hz to 1kHz) DS4303 TURN-ON TRANSIENT DS4303 LOAD TRANSIENT (VOUT = 3.3V, VCC = 3.6V) 5 3.5 VOLTS 4 3 DS4303 toc12 4.0 DS4303 toc10 6 2 +1mA 3.0 IOUT 2.5 -1mA VCC 2.0 VOUT VOUT AC-COUPLED 200mV/div 1.5 1.0 COUT =100pF 1 VCC = 3.6V 0.5 VOUT = 3.0V 0 0 10 4 3 SUPPLY VOLTAGE (V) DS4303 toc11 3.30 0 -100 VOUT = 3.0 V, VCC-AC = 300mVRMS TA = +85°C -350 100 1000 1µs/div FREQUENCY (Hz) 4 -1000 -3000 -1.0 1.0 -500 IL = 0mA -4 -1.0 OUTPUT VOLTAGE CHANGE (µV) TA = -40°C 1 -3 VCC = 3.0V -4 TA = +25°C DS4303 toc09 0 2 OUTPUT VOLTAGE (mV) TA = +25°C DS4303 toc06 3 0 DS4303 toc05 4 OUTPUT VOLTAGE CHANGE (mV) 3 DS4303 toc04 5 LINE REGULATION (VOUT = 0.3V) OUTPUT VOLTAGE CHANGE (µV) LOAD REGULATION (VOUT = 0.3V) µVOUT NOISE / √Hz DS4303 Voltage Sample and Infinite Hold _____________________________________________________________________ 0.2ms/div Voltage Sample and Infinite Hold (VCC = 3.3V, TA = +25°C, unless otherwise noted.) DS4303 LINE TRANSIENT (VOUT = 2.0) DS4303 SHUTDOWN TRANSIENT (VOUT = 3.3V) DS4303 toc14 DS4303 toc13 3.6V VCC 3.0V 500mV/div VOUT AC-COUPLED 200mV/div VOUT VCC COUT = 100pF 2ms/div 0.2ms/div DS4303 NORMALIZED VOUT vs. TEMPERATURE (VOUT = 0.4V) DS4303 VOUT ADJUST TRANSIENT (VCC = 3.6V, VIN = 3.3V) DS4303 toc15 DS4303 toc16 2V/div 1.008 ADJ VOUT (V/V) 1.003 0.998 1V/div VOUT 0.993 VCC = 3.3V 0.988 -15 -40 5ms/div 10 35 60 85 TEMPERATURE (°C) DS4303 NORMALIZED VOUT vs. TEMPERATURE (VOUT = 3.0V) DS4303 toc17 1.0005 1.0000 VOUT (V/V) 0.9995 0.9990 0.9985 0.9980 0.9975 0.9970 VCC = 3.3V 0.9965 -40 -15 10 35 60 85 TEMPERATURE (°C) _____________________________________________________________________ 5 DS4303 Typical Operating Characteristics (continued) Voltage Sample and Infinite Hold Detailed Description DS4303 Pin Description PIN NAME 1 ADJ 2 GND 3 VIN 4 VOUT Voltage Output 5 VCC Power-Supply Voltage The DS4303 provides a precise, NV output voltage, VOUT, making it an ideal solution for factory calibration of embedded systems. The DS4303 output voltage can be adjusted over almost the entire operating supply range of the device, and it can be precisely set to within ±1mV. A graphical description of the DS4303 is provided in the block diagram. During factory calibration, a simple adjustment procedure must be followed. This entire procedure includes setting VIN, toggling ADJ, waiting as VOUT self-adjusts, and waiting for the completion of the EEPROM storage cycle (See the timing diagram in Figure 1). At the start of calibration, a voltage must be placed on VIN. This voltage needs to be completely stable before the adjustment procedure begins, and it must remain stable throughout the entire adjustment procedure. The DS4303 will start its self-adjust procedure when the ADJ pin is pulled low and held low for at least tADJ, after which it can be released at any time. Once ADJ has been released, it should not be toggled again for the remainder of the adjustment procedure. After the falling edge on ADJ and the wait time, tADJ, the VOUT self-adjust period begins. The length of the VOUT selfadjust period can be determined using the formula ∆V x tST, where ∆V is | VOUT OLD - VOUT NEW |. FUNCTION Adjust Control Input Ground Sample Voltage Input Block Diagram VCC DS4303 RPU ADJ ADC AND CONTROL VOUT 12-BIT DAC VIN VCC RPD VCC VREF EEPROM GND ∆VOUT ∆VOUT VOUT ∆VOUT x tST ∆VOUT x tST VIN tW tW ADJ tADJ tADJ tADJ FIRST PROGRAMMING CYCLE ADDITIONAL PROGRAMMING CYCLES (IF REQUIRED) Figure 1. Timing Diagram 6 _____________________________________________________________________ Voltage Sample and Infinite Hold DEVICE UNDER TEST (DUT) DS4303 STEP 1: SET REFERENCE VOLTAGE EEPROM DIGITALLY CONTROLLED VOLTAGE SOURCE DIGITAL PIN DRIVER VOLTAGE SAMPLE AND INFINITE HOLD VOUT GND STEP 3: DETERMINE IF THE REFERENCE VOLTAGE NEEDS ADJUSTMENT BED-OF-NAILS TEST ACCESS DIGITALLY CONTROLLED MEASUREMENT 2.4V TO 3.6V VCC VIN ADJ STEP 2: TOGGLE ADJ DS4303 AUTOMATED TEST EQUIPMENT PARAMETER MEASURED DURING CALIBRATION CIRCUITRY REQUIRING VOLTAGE ADJUSTMENT Figure 2. Application Circuit During the VOUT self-adjust period, the DS4303 internally adjusts the onboard DAC until VOUT matches VIN. After VOUT has stabilized to within the tracking accuracy, VOUTTA, of VIN, it will be automatically stored in EEPROM. The storage period lasts for the duration of the EEPROM write time, tW. After the first adjustment procedure has completed, V OUT can be measured, and if necessary VIN can be readjusted and the entire adjustment procedure can be repeated to fine-tune VOUT within the VOUTQ range. Following each self-adjust procedure, VOUT is saved indefinitely, even if the DS4303 is power cycled. Automated Programming Procedure Figure 2 details an example of how the DS4303 can be adjusted in an application. During factory alignment, a three/four-node bed-of-nails is used to: (1) provide the adjustment voltage through the VIN pin, (2) control the ADJ input, and (3) sense the needed feedback parameter. During manufacture, an automated test procedure adjusts VOUT, by changing VIN, until the feedback parameter is optimized. After the bed-of-nails operation is complete, both the VIN and ADJ inputs are left open circuit. VOUT can be readjusted at any time by following the same procedure. The closed-loop nature of the adjustment process removes all the system inaccuracies such as resistor tolerances, amplifier offsets, gain mismatches, and even the inaccuracies in the automated equipment that provides the reference voltage. Typical Operating Circuit The typical operating circuit shows an example of how the DS4303 can replace most existing calibration solutions. Many power supplies use a shunt voltage reference to provide the internal reference voltage, and fine-tune adjustments are often made with hand-selected discrete resistors. The DS4303 replaces this cumbersome arrangement with a solution that is capable of being adjusted by automated techniques. An additional benefit of the DS4303 is the ability to provide a much lower voltage (down to 300mV) than is possible with shunt voltage references. Another benefit of the DS4303 is the ability to be adjusted after the unit has been fully assembled and tested, resulting in a much more flexible manufacturing arrangement, lower inventory costs, and a quicker time-to-market. _____________________________________________________________________ 7 DS4303 Voltage Sample and Infinite Hold Chip Topology Layout Considerations To prevent an inadvertent programming cycle from occurring during power-up, minimize capacitive loading on the ADJ pin. A large capacitance on this pin could potentially hold ADJ in a low state long enough that a programming cycle is initiated. TRANSISTOR COUNT: 6001 SUBSTRATE CONNECTED TO GROUND Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor is used on the IC power-supply pin. Typical values of decoupling capacitors are 0.01µF or 0.1µF. Use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the VCC and GND pins of the IC to minimize lead inductance. Package Information For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. is a registered trademark of Dallas Semiconductor Corporation.