General Description
The RTQ2569 is a high input voltage (36V), low quiescent current (2µA), low-dropout linear regulation(LDO) capable of sourcing 100mA. This document explains the function and use of the RTQ2569 evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to suit individual requirements
Performance Specification Summary
Summary of the RTQ2569-33GQW-QA Evaluation Board performance specificiaiton is provided in Table 1. The ambient temperature is 25°C.
Table 1. RTQ2569GQW Evaluation Board Performance Specification Summary
|
Specification
|
Test Conditions
|
Min
|
Typ
|
Max
|
Unit
|
|
Input Voltage Range
|
|
3.3
|
--
|
36
|
V
|
|
Output Current
|
|
0
|
--
|
0.1
|
A
|
|
Default Output Voltage
|
|
--
|
3.3
|
--
|
V
|
|
Dropout Voltage
|
VCC = VOUT, VOUT ≥ 3.5V, ILOAD = 10mA
|
--
|
0.2
|
0.36
|
V
|
|
VCC Consumption Current
|
VCC = VEN = 15V, VOUT ≤ 5.5V, ILOAD = 0mA
|
--
|
2
|
3.5
|
µA
|
|
Line Regulation
|
VOUT + 1 < VCC < 36V, ILOAD = 1mA
|
--
|
0.04
|
0.6
|
%
|
|
Load Regulation
|
VCC = VOUT + 4V, 0mA < ILOAD < 100mA
-40°C ≤ TJ ≤ 105°C
|
--
|
--
|
1
|
%
|
|
Output Current Limit
|
VCC = VOUT+ 6V
|
200
|
275
|
350
|
mA
|
Power-up Procedure
Suggestion Required Equipments
- RTQ2569-33GQW-QA Evaluation Board
- DC power supply capable of at least 30V and 0.2A
- Electronic load capable of 6A
- Function Generator
- Oscilloscope
Quick Start Procedures
The Evaluation Board is fully assembled and tested. Follow the steps below to verify board operation. Do not turn on supplies until all connections are made. When measuring the output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the output voltage ripple by touching the probe tip and ground ring directly across the last output capacitor.
Proper measurement equipment setup and follow the procedure below.
1) With power off, connect the input power supply to VIN and GND pins.
2) With power off, connect the electronic load between the VOUT and nearest GND pins.
3) Turn on the power supply at the input. Make sure that the input voltage does not exceeds 30V on the Evaluation Board.
4) Check for the proper output voltage using a voltmeter.
5) Once the proper output voltage is established, adjust the load within the operating ranges and observe the output voltage regulation, ripple voltage, efficiency and other performance.
Detailed Description of Hardware
Headers Description and Placement
Carefully inspect all the components used in the EVB according to the following Bill of Materials table, and then make sure all the components are undamaged and correctly installed. If there is any missing or damaged component, which may occur during transportation, please contact our distributors or e-mail us at evb_service@richtek.com.
Test Points
The EVB is provided with the test points and pin names listed in the table below.
|
Test Point/
Pin Name
|
Function
|
|
VCC
|
Input voltage.
|
|
VOUT
|
Output voltage.
|
|
GND
|
Ground.
|
|
EN
|
Enable test point.
|
|
JP1
|
EN jumper. Connect EN to ground to disable, open to enable.
|
Bill of Materials
|
VIN = 12V, VOUT = 5.0V, IOUT = 0.5A, fSW = 500kHz
|
|
Reference
|
Count
|
Part Number
|
Value
|
Description
|
Package
|
Manufacturer
|
|
U1
|
1
|
RTQ2569-33GQW-QA
|
RTQ2569-QA
|
LDO
|
WDFN-8L 3x3
|
RICHTEK
|
|
C1
|
1
|
0805B105K500CT
|
1µF
|
Capacitor, Ceramic, 50V, X7R
|
0805
|
WALSN
|
|
C2
|
1
|
GRM188R61C225KE15D
|
2.2µF
|
Capacitor, Ceramic, 16V, X7R
|
0603
|
MURATA
|
|
R3
|
1
|
WR06X1003FTL
|
100k
|
Resistor, Chip, 1/10W, 1%
|
0603
|
WALSIN
|
Typical Applications
EVB Schematic Diagram
1. The capacitance values of the input and output capacitors will influence the input and output voltage ripple.
2. MLCC capacitors have degrading capacitance at DC bias voltage, and especially smaller size MLCC capacitors will have much lower capacitance.
Measure Result
|
Output Voltage vs. Temperature
|
Output Voltage vs. Output Current
|
|
|
|
|
Dropout Voltage vs. Output Current
|
Ground Current vs. Output Current
|
|
|
|
|
Power On from VCC, IOUT = 0A
|
Power On from VCC, IOUT = 0.1A
|
|
|
|
|
PSRR vs. Frequency
|
Output Spectral Noise Density
|
|
|
|
|
Clamped Load Dump
|
|
|
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 output voltage ripple by touching the probe tip directly across the output capacitor.
Evaluation Board Layout
Figure 1 to Figure 2 are RTQ2569 Evaluation Board layout. This board size is 70mm x 50mm and is constructed on two-layer PCB, outer layers with 2 oz. Cu and inner layers with 1 oz. Cu.
Figure 1. Top View
Figure 2. Bottom View