The REF30xx is a precision, low-power, low-dropout voltage, reference family available in a tiny 3-pin SOT-23 package. The REF30xx offers excellent temperature drift and initial accuracy while operating at a quiescent current of 42 µA (typical).
The low power consumption and the relatively high precision make the REF30xx very attractive for loop-powered industrial applications such as pressure and temperature transmitter applications. The REF30xx is easy to use in intrinsically safe and explosion-proof applications because it does not require a load capacitor to be stable. The REF30xx is specified over the extended industrial temperature range of –40°C to +125°C.
The REF30xx operates with supplies within 1 mV of output voltage under zero-load conditions. Engineers can use the low dropout, small size, and low power consumption of the REF30xx in portable and battery-powered applications.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
REF30xx | SOT-23 (3) | 2.92 mm × 1.30 mm |
Changes from Revision H (February 2018) to Revision I (July 2022)
Changes from Revision G (November 2015) to Revision H (February 2018)
Changes from Revision F (August 2008) to Revision G (November 2015)
PART NUMBER | VOLTAGE (V) |
---|---|
REF3012 | 1.25 |
REF3020 | 2.048 |
REF3025 | 2.5 |
REF3030 | 3.0 |
REF3033 | 3.3 |
REF3040 | 4.096 |
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NO. | NAME | ||
1 | IN | Input | Input supply voltage |
2 | OUT | Output | Reference output voltage |
3 | GND | — | Ground |
MIN | MAX | UNIT | |
---|---|---|---|
Supply voltage, V+ to V– | 7.0 | V | |
Output short-circuit current(2) | Continuous | ||
Operating temperature | –40 | 125 | °C |
Junction temperature | 150 | °C | |
Storage temperature, Tstg | –65 | 150 | °C |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | ±4000 | V |
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) | ±1500 |
MIN | NOM | MAX | UNIT | |||
---|---|---|---|---|---|---|
VIN | Input voltage | VREF + 0.05(1) | 5.5 | V | ||
ILOAD | Load current | 25 | mA | |||
TA | Operating temperature | –40 | 125 | °C |
THERMAL METRIC(1) | REF30xx | UNIT | |
---|---|---|---|
DBZ (SOT-23) | |||
3 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 297.3 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 128.5 | °C/W |
RθJB | Junction-to-board thermal resistance | 91.7 | °C/W |
ψJT | Junction-to-top characterization parameter | 12.8 | °C/W |
ψJB | Junction-to-board characterization parameter | 90.3 | °C/W |
RθJC(bot) | Junction-to-case (bottom) thermal resistance | N/A | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | ||
---|---|---|---|---|---|---|---|
REF3012 (1.25 V)(1) | |||||||
VOUT | Output voltage | 1.2475 | 1.25 | 1.2525 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 14 | μVPP | ||||
f = 10 Hz to 10 kHz | 42 | µVrms | |||||
Line regulation | 1.8 V ≤ VIN ≤ 5.5 V | 60 | 190 | µV/V | |||
REF3020 (2.048 V) | |||||||
VOUT | Output voltage | 2.044 | 2.048 | 2.052 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 23 | μVPP | ||||
f = 10 Hz to 10 kHz | 65 | µVrms | |||||
Line regulation | VREF + 50 mV ≤ VIN ≤ 5.5 V | 110 | 290 | µV/V | |||
REF3025 (2.5 V) | |||||||
VOUT | Output voltage | 2.495 | 2.50 | 2.505 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 28 | μVPP | ||||
f = 10 Hz to 10 kHz | 80 | µVrms | |||||
Line regulation | VREF + 50 mV ≤ VIN ≤ 5.5 V | 120 | 325 | µV/V | |||
REF3030 (3.0 V) | |||||||
VOUT | Output voltage | 2.994 | 3.0 | 3.006 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 33 | μVPP | ||||
f = 10 Hz to 10 kHz | 94 | µVrms | |||||
Line regulation | VREF + 50 mV ≤ VIN ≤ 5.5 V | 120 | 375 | µV/V | |||
REF3033 (3.3 V) | |||||||
VOUT | Output voltage | 3.294 | 3.30 | 3.306 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 36 | μVPP | ||||
f = 10 Hz to 10 kHz | 105 | µVrms | |||||
Line regulation | VREF + 50 mV ≤ VIN ≤ 5.5 V | 130 | 400 | µV/V | |||
REF3040 (4.096 V) | |||||||
VOUT | Output voltage | 4.088 | 4.096 | 4.104 | V | ||
Initial accuracy | 0.2% | ||||||
Output voltage noise | f = 0.1 Hz to 10 Hz | 45 | μVPP | ||||
f = 10 Hz to 10 kHz | 128 | µVrms | |||||
Line regulation | VREF + 50 mV ≤ VIN ≤ 5.5 V | 160 | 410 | µV/V | |||
REF30xx (REF3012, REF3020, REF3025, REF3030, REF30333, REF3040) | |||||||
dVOUT/dT | Output voltage temperature drift(2) | 0°C ≤ TA ≤ 70°C | 20 | 50 | ppm/°C | ||
–30°C ≤ TA ≤ +85°C | 28 | 60 | |||||
–40°C ≤ TA ≤ +85°C | 30 | 65 | |||||
–40°C ≤ TA ≤ +125°C | 35 | 75 | |||||
Long-term stability | 0000h to 1000h | 24 | ppm | ||||
1000h to 2000h | 15 | ||||||
ΔVO(ΔIL) | Load regulation(3) | 0 mA < ILOAD < 25 mA, VIN = VREF + 500 mV(1) | 3 | 100 | µV/mA | ||
dT | Thermal hysteresis(4) | 25 | 100 | ppm | |||
VIN – VOUT | Dropout voltage | 1 | 50 | mV | |||
ISC | Short-circuit current | 45 | mA | ||||
Turnon settling time | To 0.1% with CL = 1 μF | 120 | µs | ||||
POWER SUPPLY | |||||||
IQ | Quiescent current | 42 | 50 | μA | |||
–40°C ≤ TA ≤ +125°C | 59 |
at TA = 25°C, VIN = 5 V, and REF3025 used for typical characteristics (unless otherwise noted)
0°C to 70°C |
ILOAD = 25 mA |
CL = 0, 3-V startup | ||
CL = 0 | ||
CL = 1 μF | ||
–40°C to +125°C |
No Load |
CL = 0, 5-V startup | ||
CL = 0 | ||
CL = 1 μF | ||
The REF30xx is a series, CMOS, precision bandgap voltage reference. Its basic topology is shown in the Section 8.2 section. Transistors Q1 and Q2 are biased so that the current density of Q1 is greater than that of Q2. The difference of the two base-emitter voltages, Vbe1 – Vbe2, has a positive temperature coefficient and is forced across resistor R1. This voltage is gained up and added to the base-emitter voltage of Q2, which has a negative coefficient. The resulting output voltage is virtually independent of temperature. The curvature of the bandgap voltage, as shown in Figure 7-3, is due to the slightly nonlinear temperature coefficient of the base-emitter voltage of Q2.
The REF30xx family of references features an extremely low dropout voltage. With the exception of the REF3012, which has a minimum supply requirement of 1.8 V, the REF30xx can be operated with a supply of only 1 mV above the output voltage in an unloaded condition. For loaded conditions, a typical dropout voltage versus load is shown on the front page.
The REF30xx features a low quiescent current that is extremely stable over changes in both temperature and supply. The typical room temperature quiescent current is 42 μA, and the maximum quiescent current over temperature is just 59 μA. Additionally, the quiescent current typically changes less than 2.5 μA over the entire supply range, as shown in Figure 8-1.
Supply voltages below the specified levels can cause the REF30xx to momentarily draw currents greater than the typical quiescent current. Use a power supply with a fast rising edge and low output impedance to easily prevent this issue.