loading

2.3µA IQ/High Switching Frequency RBCOT Buck Converter for Fast Transient Response

EVB_RT5716P-BBA

Share
ACTIVE

The RT5716 is a synchronous step-down converter with 4MHz typical switching frequency. This document only specifies the RT5716 in WL-CSP package. It explains the function and operation of the RT5716 evaluation board (EVB) and provides information about the setting of the evaluation board.

General Description

The RT5716 is a synchronous step-down converter with 4MHz typical switching frequency. This document only specifies the RT5716 in WL-CSP package. It explains the function and operation of the RT5716 evaluation board (EVB) and provides information about the setting of the evaluation board.



Performance Specifications

Performance specifications of the RT5716 are listed in Table 1.

(VIN = 3.6V, CIN = 4.7µF, COUT = 4.7µF x 2, L = 0.47µH, TJ = -40°C to 125°C, typical values are at TJ = 25°C, unless otherwise specified)


Table 1. Performance Specifications of the RT5716

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit

Supply Input Voltage

VIN

1.8

--

5.5

V

Output Current

IOUT

VIN ≥ 2.3V

For RT5716P-ABA, RT5716P-BBA, RT5716P-CBA, RT5716P-DBA

--

--

1

A

VIN < 2.3V

For RT5716P-ABA, RT5716P-BBA, RT5716P-CBA, RT5716P-DBA

--

--

0.7

A

Switching Frequency

fSW

--

4

--

MHz

Quiescent Current into VIN Pin (Non-Switching)

IQ_IN-NONSW

EN = VIN, VOUT = 1.2V, IOUT = 0A, RSEL/MODE = GND, TJ = -40°C to 85°C

--

2.3

3.7

µA

Quiescent Current into VIN Pin (Switching)

IQ_IN-SW

EN = VIN, VOUT = 1.2V, IOUT = 0A, RSEL/MODE = GND

--

2.5

--

Shutdown Current

ISHDN

EN = GND, RSEL/MODE = GND,

TJ = -40°C to 85°C

--

55

290

nA



Power-up Procedure

Equipment Required

  • RT5716 Evaluation Board
  • DC power supply capable of at least 5.5V and 3A
  • Electronic load capable of 1A
  • Function Generator
  • Oscilloscope

Quick Start Procedures

The evaluation board is fully assembled and tested. Follow the steps listed below to verify its functionality. Do not turn on power supplies until all equipment is well-connected. Do not measure the output voltage ripple with a long ground lead on the oscilloscope probe. Instead, touch the probe tip and ground ring directly across the output capacitor.

The setup procedures are listed below.

1) Connect JP4 between the RSEL/MODE pin and GND to set output voltage level.

2) Connect the power supply to VIN and GND pins and the electronic load to the VO and nearest GND pins before power on.

3) Turn on the input power supply and make sure that the input voltage does not exceed 5.5V.

4) Enable/disable the RT5716 by the EN pin. When the EN pin is higher than the threshold voltage of logic-high, the IC operates at normal mode; When the EN pin goes low, the RT5716 enters shutdown mode. In shutdown mode, the converter stops switching, internal control circuitry is turned off and discharge function is triggered.

5) When RT5716 starts up, the RSEL/MODE pin operates as an input used for mode selection. When connecting the RSEL/MODE pin to L, the RT5716 operates at Auto Mode, which is PFM mode; On the other hand, the RT5716 operates at FPWM mode when connecting the RSEL/MODE pin to H.

6) Check the output voltage by a voltmeter.

7) Adjust the load within the operating range and measure the output voltage regulation, ripple voltage, power efficiency and other performances.



Detailed Description of Hardware

Headers Description and Placement

一張含有 文字, 電子產品, 螢幕擷取畫面, 圓形 的圖片

自動產生的描述

Carefully inspect all the components used on the EVB according to the following Bill of Materials table, and 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 test points and pin names are listed in the table below.

Test Point/

Pin Name

Function

VIN

Input voltage.

VO

Output voltage.

GND

Ground.

EN

Enable pin.

RSEL/MODE

Output voltage level and operation mode selection pin.



Bill of Materials

RT5716P-ABA/RT5716P-BBA/RT5716P-CBA/RT5716P-DBA

Reference

Qty

Part Number

Value

Description

Package

Manufacturer

U1

1

RT5716P-ABA

RT5716P-BBA

RT5716P-CBA

RT5716P-DBA

RT5716

Step-Down Converter

TWL-CSP-6B 0.69x1.04 (BSC)

RICHTEK

C3, C4, C5

3

GRM155R60J475ME47D

4.7µF

Capacitor, Ceramic, 6.3V, X5R

0402

Murata

C9

1

GRM21BC80J476ME01

47µF

Capacitor, Ceramic, 6.3V, X6S

0805

Murata

L1

1

DFE18SANR47MG0L

0.47µH

0.47µH

0603

Murata

JP21

16

RC0201FR-0710KL

(Resistor E96 series)

Refer to Table 2

1%, TC ±200ppm

0201

YAGEO


Output Voltage Selection

The RT5716 provides 1 fixed and 16 different levels of VOUT which can be set by an external resistor connected between the RSEL/MODE pin and GND. Table 2 indicates the setting to different output voltage level.


Table 2. Output Voltage Setting

Type

Output-1 (V)

Output-2 (V)

Output-3 (V)

Output-4 (V)

RSEL (kW) *

Level

0.4V to 3.3V

0.4V to 0.775V

0.8V to 1.55V

1.8 V to 3.3V

Min

Nom

Max

0

3.3

0.7

1.2

1.8

Connected to GND

(No resistor needed)

1

0.4

0.4

0.8

1.8

9.9

10

10.1

2

0.58

0.425

0.85

1.9

12

12.1

12.2

3

0.6

0.45

0.9

2

15.2

15.4

15.6

4

0.7

0.475

0.95

2.1

18.5

18.7

18.9

5

0.75

0.5

1

2.2

23.5

23.7

23.9

6

0.8

0.525

1.05

2.3

28.4

28.7

29

7

1.1

0.55

1.1

2.4

36.1

36.5

36.9

8

1.2

0.575

1.15

2.5

43.8

44.2

44.6

9

1.3

0.6

1.2

2.6

55.6

56.2

56.8

10

1.5

0.625

1.25

2.7

67.4

68.1

68.8

11

1.6

0.65

1.3

2.8

85.7

86.6

87.5

12

1.8

0.675

1.35

2.9

104

105

106.1

13

1.9

0.7

1.4

3

131.7

133

134.3

14

2.5

0.725

1.45

3.1

160.4

162

163.6

15

3

0.75

1.5

3.2

203

205

207.1

16

3.3

0.775

1.55

3.3

³249

³249

³249

*: E96 resistor series, 1% accuracy, temperature coefficient better or equal than ±200 ppm/°C.



Typical Applications

EVB Schematic Diagram

Technical Document Image Preview


1. The capacitance of the input and output will influence the input and output voltage ripple, respectively.

2. MLCC capacitance degrades at different DC bias voltage. The smaller package size of MLCC capacitors, the more capacitance degradation there would be under the same test condition.


Measure Result

The following curves and waveforms are the measure results of the RT5716P-ABA.

Quiescent Current vs. Input Voltage

Shutdown Current vs. Input Voltage

Technical Document Image Preview

Technical Document Image Preview

Efficiency vs. Output Current

Output Voltage vs. Output Current

Technical Document Image Preview

Technical Document Image Preview

Output Voltage vs. Output Current

Switching Frequency vs. Output Current

Technical Document Image Preview

Technical Document Image Preview

Power Save Mode Operation

Pulse Width Modulation Operation

Technical Document Image Preview

Technical Document Image Preview

Power On with Light Load

AC Load Sweep at Power Save Mode

Technical Document Image Preview

Technical Document Image Preview

Load Transient Response

Load Transient Response

Technical Document Image Preview

Technical Document Image Preview


Note: Do not measure the output voltage ripple with a long ground lead on the oscilloscope probe. Instead, touch the probe tip and ground ring directly across the output capacitor.



Evaluation Board Layout

Figure 1 to Figure 4 are the RT5716 evaluation board layout for TWL-CSP package. This board size is 84.6mm x 55.7mm and is constructed on four-layer PCB.

一張含有 文字, 螢幕擷取畫面, 圓形, 數字 的圖片

自動產生的描述

Figure 1. Top View (1st layer)


一張含有 螢幕擷取畫面, 文字, 圓形 的圖片

自動產生的描述

Figure 2. PCB Layout—Inner Side (2nd Layer)


一張含有 螢幕擷取畫面, 文字, 圓形 的圖片

自動產生的描述

Figure 3. PCB Layout—Inner Side (3rd Layer)


一張含有 螢幕擷取畫面, 文字, 圓形, 圖表 的圖片

自動產生的描述

Figure 4. Bottom View (4th Layer)

Title Last Update Share Download
Evaluation Board User Guide 2024/04/29
Bill of Materials 2024/04/29
Schematic 2024/04/29
Gerber File 2024/04/29
RT5716
RT5716

The RT5716 is a high switching frequency synchronous step-down converter with a quiescent current of 2.3μA. The device uses RBCOT (Ripple-Based Constant-On-Time) control to enhance load/line transient response to be optimized over a wide range of loads and output capacitors.

The RT5716 input voltage range is from 1.8V to 5.5V, making it suitable for battery applications. It provides 16 selectable output voltage levels by connecting the resistor between RSEL/MODE pin and GND. The PFM design can maintain high efficiency during the light load. At higher load conditions, the device automatically switches to PWM. The device can deliver up to 0.6/1A loading current. In shutdown mode, the supply current is typically 55nA, excellent in reducing power consumption.

The RT5716 is available in TWL-CSP-6B 0.69x1.04 (BSC) and WDFN-6L 1.5x1.5 (FC) packages that have the smallest packages for small size applications.

The recommended junction temperature range is -40°C to 125°C, and the ambient temperature range is -40°C to 85°C.

Part NumberDistributorStockBuy From Authorized Distributor
EVB_RT5716P-BBA Digikey 5 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
IC
Part NumberPackage TypePackage Qty.Free SampleDistributorStockBuy From Authorized Distributor
RT5716P-ABATWL-CSP0.69x1.04-63,000 Sample Digikey 3,000 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
RT5716P-BBATWL-CSP0.69x1.04-63,000 Sample Digikey 3,000 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
RT5716P-CBATWL-CSP0.69x1.04-63,000 Sample Digikey 2,880 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
RT5716P-DBATWL-CSP0.69x1.04-63,000 Sample Digikey 3,000 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
TOP