MAXIM Manuals

The MAX873/MAX875/MAX876 precision 2.5V, 5V, and 10V references offer excellent accuracy and very low power consumption. Extremely low temperature drift combined with excellent line and load regulation permit stable operation over a wide range of electrical and environmental conditions. Operation for the MAX873 is guar- anteed with a +4.5V supply, making the part ideal in systems running from a +5V ±10% supply. Low 10Hz to 1kHz noise—typically 3.8µVRMS, 9µVRMS, and 18µVRMS, respectively, for the MAX873, MAX875, MAX876—make the parts suitable for 12-bit data-acquisition systems. A TRIM pin facilitates adjustment of the reference voltage over a ±6% range, using only a 100kΩ potentiometer. A voltage output proportional to temperature provides a source for temperature compensation circuits, tempera- ture warning circuits, and other applications.

The MAX6325/MAX6341/MAX6350 are low-noise, precision voltage references with extremely low, 0.5ppm/°C typical temperature coefficients and excellent, ±0.02% initial accuracy. These devices feature buried-zener technology for lowest noise performance. Load-regulation specifications are guaranteed for source and sink currents up to 15mA. Excellent line and load regulation and low output impedance at high frequencies make them ideal for high-resolution data-conversion systems up to 16 bits. The MAX6325 is set for a 2.5V output, the MAX6341 is set for a 4.096V output, and the MAX6350 is set for a 5V output. All three provide for the option of external trimming and noise reduction.

The MAX6220 is a low-noise, precision voltage reference with extremely low 20ppm/°C temperature coefficient over the automotive temperature range (-40°C to +125°C) and excellent ±0.1% initial accuracy. This device features buried-zener technology for low noise performance. The load-regulation specification is guaranteed for source and sink currents up to 15mA. Excellent line and load regulation and low output impedance at high frequency make the MAX6220 ideal for high-resolution data-conversion systems up to 16 bits. The MAX6220 is set for 2.5V, 4.096V, and 5.0V outputs.

The MAX6033 is an ultra-high-precision series voltage reference featuring a low temperature coefficient (7ppm/°C) and a low dropout voltage (200mV).

The MAX6035 is a high-voltage, precision micropower voltage reference

The MAX6133 high-precision, low-power, low-dropout voltage reference features a low 3ppm/°C (max) temperature coefficient and a low dropout voltage (200mV, max). This series-mode device features bandgap technology for low-noise performance and excellent accuracy. Load regulation specifications are guaranteed for source currents up to 15mA. The laser-trimmed, high-stability thin-film resistors, together with post-package trimming, guarantee an excellent initial accuracy specification (0.04%, max). The MAX6133 is a series voltage reference and consumes only 40µA of supply current (virtually independent of supply voltage). Series-mode references save system power and use minimal external components compared to 2-terminal shunt references. The MAX6133 is available in 8-pin µMAX and SO packages. The unique blend of tiny packaging and excellent precision performance make these parts ideally suited for portable and communication applications.

The MAX6143 is a low-noise, high-precision voltage reference. The device features a proprietary temperature-coefficient curvature-correction circuit and laser-trimmed thin-film resistors that result in a very low 3ppm/°C temperature coefficient and excellent ±0.06% initial accuracy. The MAX6143 provides a TEMP output where the output voltage is proportional to die temperature, making the device suitable for a wide variety of temperature-sensing applications. The device also provides a TRIM input, allowing fine trimming of the output voltage with a resistive-divider network. Low temperature drift and low noise make the MAX6143 ideal for use with high-resolution A/D or D/A converters. The MAX6143 provides accurate preset +2.5V, +3.3V, +4.096V, +5.0V, and +10V reference voltages and accepts input voltages up to +40V. The device draws 340µA of supply current and sources 30mA or sinks 2mA of load current. The active-low shutdown feature (SHDN) reduces supply current to 0.01µA. The MAX6143 uses bandgap technology for low-noise performance and excellent accuracy. The MAX6143 does not require an output bypass capacitor for stability, and is stable with capacitive loads up to 100µF. Eliminating the output bypass capacitor saves valuable board area in space-critical applications. The MAX6143 is available in an 8-pin SO package and operates over the automotive (-40°C to +125°C) temperature range.

The MAX6043 precision voltage reference provides accurate preset +2.5V, +3.3V, +4.096V, +5.0V, and +10V reference voltages from up to +40V input voltages

The MAX6034 family of precision, low-dropout, micropower voltage references are available in the miniature 3-pin SC70 surface-mount package. They feature a proprietary temperature coefficient curvature-correction circuit and laser-trimmed, thin-film resistors that result in a low temperature coefficient of 30ppm/°C (max) and initial accuracy of ±0.20% (max). These devices are available over the extended temperature range of -40°C to +85°C. The MAX6034 family of series-mode voltage references typically draw only 90µA of supply current and can source 1mA and sink 200µA of load current. Unlike conventional shunt-mode (two terminal) references that waste supply current and require an external resistor, devices in the MAX6034 family offer supply current that is virtually independent of supply voltage (16µA/V, max variation) and do not require an external resistor. These internally compensated devices do not require an external compensation capacitor, but are stable with up to 1µF of load capacitance. Eliminating the external compensation capacitor saves valuable board space in space-critical applications. The low dropout voltage and supply-independent, ultra-low supply current make the MAX6034 ideal for battery-powered applications.

The MAX6129 micropower, low-dropout bandgap voltage reference combines ultra-low supply current and low drift in a miniature 5-pin SOT23 surface-mount package that uses 70% less board space than comparable devices in an SO package. This series-mode voltage reference sources up to 4mA and sinks up to 1mA of load current. A wide 2.5V to 12.6V supply range, ultra-low 5.25µA (max) supply current, and a low 200mV dropout voltage make these devices ideal for battery-operated systems. An initial accuracy of 0.4% and a 40ppm/°C (max) tem- perature coefficient make the MAX6129 suitable for precision applications. Additionally, an internal com- pensation capacitor eliminates the need for an external compensation capacitor and ensures stability with load capacitances up to 10µF. The MAX6129 provides six output voltages of 2.048V, 2.5V, 3V, 3.3V, 4.096V, and 5V. The MAX6129 is avail- able in a 5-pin SOT23 package and in die form.

The MAX6126 is an ultra-low-noise, high-precision, low-dropout voltage reference. It features curvature-correction circuitry and high-stability, laser-trimmed, thin-film resistors resulting in a temperature coefficient of 3ppm/°C (max) and an initial accuracy of ±0.02% (max). The proprietary low-noise reference architecture produces low flicker noise of 1.3µVP-P and wideband noise as low as 60nV/√Hz (2.048V output) without increased supply current. Adding a 0.1µF capacitor at the noise reduction pin improves wideband noise to 35nV/√Hz and AC power-supply rejection. The MAX6126 operates from a wide 2.7V to 12.6V supply voltage range with load-regulation specifications guaranteed to be less than 0.025Ω for sink and source currents up to 10mA. It is available over the automotive temperature range of -40°C to +125°C and typically draws 380µA of supply current. The MAX6126 is stable with 0.1µF to 10µF of load capacitance.

The MAX6120 is the lowest-power 1.2V, precision, three-terminal voltage reference offered in a SOT23 package.

The MAX6520 is the lowest-power 1.2V, precision, three-terminal voltage reference offered in a SOT23-3 package. Ideal for 3V battery-powered equipment where power conservation is critical, the MAX6520 is a low-power alternative to existing two-terminal shunt references. Unlike two-terminal references that throw away battery current and require an external series resistor, the MAX6520 has a 70µA maximum supply current (typically only 50µA) that is independent of the input voltage. This feature translates to maximum efficiency at all battery voltages. The MAX6520 operates from a supply voltage as low as 2.4V, and initial accuracy is ±1% for the SOT23 package. Output voltage temperature coefficient is typically only 25ppm/°C, and is guaranteed to be less than 50ppm/°C in the SOT23 package.

The MAX6190-MAX6195/MAX6198 precision, micropower, low-dropout voltage references offer high initial accuracy and very low temperature coefficient through a proprietary curvature-correction circuit and laser-trimmed precision thin-film resistors. These series-mode bandgap references draw a maxi- mum of only 35µA quiescent supply current, making them ideal for battery-powered instruments. They offer a supply current that is virtually immune to input volt- age variations. Load-regulation specifications are guaranteed for source and sink currents up to 500µA. These devices are internally compensated, making them ideal for applications that require fast settling, and are stable with capacitive loads up to 2.2nF.