LINEAR TECHNOLOGY LT3462ES6 and LT3462AES6 Inverting DC/DC Converters User Guide
- June 9, 2024
- LINEAR TECHNOLOGY
Table of Contents
LINEAR TECHNOLOGY LT3462ES6 and LT3462AES6 Inverting DC/DC Converters
DESCRIPTION
Demonstration circuit 670 features two high frequency, monolithic LT3462 and LT3462A inverting converters. Both circuits have 5V input voltage and -5V output volt-age with 100mA maximum output current. Negative SEPIC converter topology is used to minimize the input and output voltage ripple. The LT3462 circuit is opti-mized for best efficiency with the 1.2MHz switching fre- quency. The LT3462A circuit is optimized for minimum circuit size and profile with the 2.7MHz switching fre-quency. Both circuits have small footprint size because of the integrated Schottky diode inside the ICs.
Design files for this circuit board are available. Call the LTC factory.
LT is a trademark of Linear Technology Corporation
Table 1. Performance Summary (TA = 25°C)
| PARAMETER | CONDITION | VALUE |
|---|---|---|
| Input Voltage | 5V ± 10% | |
| Output Voltage VOUT | IOUT = 0A to 100mA | -5V ± 3% |
| Maximum Output Current | 100mA | |
| Typical Output Ripple Voltage | IOUT = 50mA , 20MHz BW | 10mVP–P |
| Nominal Switching Frequency | LT3462ES6 | 1.2MHz |
| LT3462AES6 | 2.7MHz | |
| Efficiency | LT3462ES6, VIN = 5V, IOUT = 100mA | 71% Typical |
| LT3462AES6, VIN = 5V, IOUT = 100mA | 61% Typical |
QUICK START PROCEDURE
Demonstration circuit 670 is easy to set up to evaluate the performance of the
LT3462 and LT3462A. Refer to Figure 1 for proper measurement equipment setup
and follow the procedure below:
NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the Vin or Vout and GND terminals. See Figure 2 for proper scope probe technique.
-
Place both ON/OFF jumpers in the ON position.
-
With power off, connect the 5V input power supply to VIN and GND. Connect the load between VOUT and GND. Preset the load current at 0A (minimum).
-
Turn on the power at the input.
NOTE: Make sure that the input voltage does not exceed 5.5V. -
Check for the proper output voltages. Vout = -4.85V to -5.15V.
NOTE: If there is no output, temporarily disconnect the load to make sure that the load is not set too high. -
Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters.
Figure 1. Proper Measurement Equipment Setup
(a) LT3462ES6 test setup, (b) LT3462AES6 test setup
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 670
LT3462ES6 / LT3462AES6 INVERTING DC/DC CONVERTERS
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