Datasheet MAX6225, MAX6241, MAX6250 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References |
| Pages / Page | 11 / 9 — Pin Description. Noise Reduction. PIN. NAME. FUNCTION. Do not use. … |
| File Format / Size | PDF / 2.2 Mb |
| Document Language | English |
Pin Description. Noise Reduction. PIN. NAME. FUNCTION. Do not use. Bypassing. Applications Information. Detailed Description
Model Line for this Datasheet
- MAX6225ACPA+ MAX6225ACSA+ MAX6225ACSA+T MAX6225AESA+ MAX6225AESA+T MAX6225AMJA MAX6225BCPA+ MAX6225BCSA+ MAX6225BCSA+T MAX6225BEPA+ MAX6225BESA+ MAX6225BESA+T
Text Version of Document
MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References
Pin Description Noise Reduction
To augment wideband noise reduction, add a 1μF capacitor
PIN NAME FUNCTION
to the NR pin (Figure 2). Larger values do not improve 1, 7, 8 I.C. Internally Connected.
Do not use
. noise appreciably (see Typical Operating Characteristics). 2 IN Positive Power-Supply Input Noise in the power-supply input can affect output noise, Noise Reduction. Optional capacitor but can be reduced by adding an optional bypass capacitor 3 NR connection for wideband noise reduction. to the IN pin and GND. Leave open if not used (Figure 2).
Bypassing
4 GND Ground The MAX6225/MAX6241/MAX6250 are stable with capacitive External Trim Input. Allows ±1% output load values from 0μF to 100μF, for all values of load 5 TRIM adjustment (Figure 1). Leave open if not current. Adding an output bypass capacitor can help reduce used. noise and output glitching caused by load transients. 6 OUT Voltage Reference Output
Applications Information Detailed Description Negative Regulator
Figure 3 shows how both a +5V and -5V precision reference
Temperature Stability
can be obtained from a single unregulated +5V supply. The MAX6225/MAX6241/MAX6250 are highly stable, A MAX681 generates approximately ±9V to operate the low-noise voltage references that use a low-power MAX6250 reference and MAX432 inverting amplifier. The temperature-compensation scheme to achieve laboratory- +5V is inverted by the MAX432 chopper-stabilized amplifier. standard temperature stability. This produces a nearly flat Resistor R1 is optional, and may be used to trim the temperature curve, yet does not require the power associated ±5V references. R2 and R4 should be matched, both in with heated references. absolute resistance and temperature coefficient. R3 is The output voltage can be trimmed a minimum of 0.6% optional, and is adjusted to set the -5V reference. by connecting a 10kΩ potentiometer between OUT and GND, and connecting its tap to the TRIM pin, as shown in Figure 1. The external trimming does not affect temperature stability. 8V TO 36V INPUT 8V TO 36V INPUT IN IN REFERENCE OUT REFERENCE OUT OUT OUT
MAX6225 MAX6225 MAX6241 MAX6241
*
MAX6250 MAX6250
NR TRIM TRIM 10kΩ NR GND 1µF GND *OPTIONAL Figure 1. Output Voltage Adjustment Figure 2. Noise-Reduction Capacitor www.maximintegrated.com Maxim Integrated │ 9
Pin Description Noise Reduction
To augment wideband noise reduction, add a 1μF capacitor
PIN NAME FUNCTION
to the NR pin (Figure 2). Larger values do not improve 1, 7, 8 I.C. Internally Connected.
Do not use
. noise appreciably (see Typical Operating Characteristics). 2 IN Positive Power-Supply Input Noise in the power-supply input can affect output noise, Noise Reduction. Optional capacitor but can be reduced by adding an optional bypass capacitor 3 NR connection for wideband noise reduction. to the IN pin and GND. Leave open if not used (Figure 2).
Bypassing
4 GND Ground The MAX6225/MAX6241/MAX6250 are stable with capacitive External Trim Input. Allows ±1% output load values from 0μF to 100μF, for all values of load 5 TRIM adjustment (Figure 1). Leave open if not current. Adding an output bypass capacitor can help reduce used. noise and output glitching caused by load transients. 6 OUT Voltage Reference Output
Applications Information Detailed Description Negative Regulator
Figure 3 shows how both a +5V and -5V precision reference
Temperature Stability
can be obtained from a single unregulated +5V supply. The MAX6225/MAX6241/MAX6250 are highly stable, A MAX681 generates approximately ±9V to operate the low-noise voltage references that use a low-power MAX6250 reference and MAX432 inverting amplifier. The temperature-compensation scheme to achieve laboratory- +5V is inverted by the MAX432 chopper-stabilized amplifier. standard temperature stability. This produces a nearly flat Resistor R1 is optional, and may be used to trim the temperature curve, yet does not require the power associated ±5V references. R2 and R4 should be matched, both in with heated references. absolute resistance and temperature coefficient. R3 is The output voltage can be trimmed a minimum of 0.6% optional, and is adjusted to set the -5V reference. by connecting a 10kΩ potentiometer between OUT and GND, and connecting its tap to the TRIM pin, as shown in Figure 1. The external trimming does not affect temperature stability. 8V TO 36V INPUT 8V TO 36V INPUT IN IN REFERENCE OUT REFERENCE OUT OUT OUT
MAX6225 MAX6225 MAX6241 MAX6241
*
MAX6250 MAX6250
NR TRIM TRIM 10kΩ NR GND 1µF GND *OPTIONAL Figure 1. Output Voltage Adjustment Figure 2. Noise-Reduction Capacitor www.maximintegrated.com Maxim Integrated │ 9
