1. Device Overview:

️· Part Numbers: MAX872 and MAX874
️· Type: Low-Dropout (LDO) Precision Voltage References
️· Key Features:
- Low quiescent current (10µA typical)
- 0.2% Initial Accuracy (at +25°C)
- Temperature-Proportional Output (TEMP)
- Adjustable output voltage via TRIM input
- Good Power-Supply Rejection Ratio (PSRR) within a specific frequency range (see graphs)

2. Electrical Characteristics & Specifications (highlights, not a full list):

️· Input Voltage (VIN): Not specified exactly, but implied to have a significant range. Important to ensure it’s above the target output voltage for proper operation.
️· Output Voltage (VOUT): Factory-trimmed for 0.2% tolerance. Can be adjusted using the TRIM input.
️· TEMP Output: Generates a voltage proportional to junction temperature.
️· Dropout Voltage: Critical for LDO operation; ensure adequate margin.
️· Power Dissipation: <100µW typical.

3. Pin Descriptions:

️· 1, 7 (I.C.): Internal Connection - No connection required.
️· 2 (VIN): Input Voltage.
️· 3 (TEMP): Temperature Output.
️· 4 (GND): Ground.
️· 5 (TRIM): Output Voltage Trim. Used to adjust output voltage.
️· 6 (VOUT): Reference Output.
️· 8 (COMP): Compensation Input. Used for capacitive load compensation.

4. Applications Information & Considerations:

️· Output Voltage Trimming: Adjustable via the TRIM input. Changing the trim voltage changes the output voltage tempco (temperature coefficient).
️· Input Ripple Reduction: Use an input filter (RC network) to reduce ripple, especially when dealing with noisy power supplies. The filter pole should be below 0.1Hz.
️· Capacitive Load Stability: A capacitor between VOUT and GND (1000pF minimum if load >300µA). A compensation capacitor (C = C_LOAD/100) between COMP and VOUT is needed for higher loads.
️· TEMP Output Usage: Can be used for temperature monitoring, LCD contrast control, ADC gain compensation, or thermal indication.
️· Start-Up Behavior: Ensure sufficient headroom on the input voltage and low source resistance to prevent excessive current draw during startup. The input voltage needs to be above the target output voltage.
️· Operating Temperature Window Comparator: A comparator circuit can monitor the TEMP output to indicate out-of-range temperature conditions.
️· Chip Topography: N.C. COMP, make no connections to these pads.

5. Key Figures and Diagrams (Refer to the original document for visual details):

️· Figure 1a & 1b: Adjusting VOUT with TRIM
️· Figure 1a: Adjusting VOUT with TRIM on the MAX872
️· Figure 1b: Adjusting VOUT with TRIM on the MAX874
️· Figure 2: Input Filter for Ripple Reduction
️· Figure 3: Operating Temperature Window Comparator

Important Notes:

️· The document is intended as an application guide and doesn’t provide complete electrical specifications.
️· Carefully review the graphs (PSRR vs. Frequency, Noise vs. Frequency, Output Voltage vs. Temperature) in the original document for detailed performance characteristics.
️· Always consult the complete datasheet for comprehensive electrical specifications and device limitations.