®
RT5707/A
Ultra-Low Quiescent Current HCOT Buck Converter
General Description
Features
The RT5707/A is a high efficiency synchronous step-down
converter featuring typ. 360nA quiescent current. It provides
Input Voltage Range : 2.2V to 5.5V
Programmable Output Voltage 8-Level
RT5707 1.2V to 3.3V
RT5707A 0.7V to 3.1V
Typ. 360nA Quiescent Current
PSM Operation
Up to 94% Efficiency
Internal Compensation
Output Voltage Discharge
Over-Current Protection
Over-Temperature Protection
Output Current
RT5707 600mA, Peak to 1A
RT5707A 400mA, Peak to 0.5A
Automatic Transition to 100% Duty Cycle Operation
high efficiency at light load down to 10mA. Its input voltage
range is from 2.2V to 5.5V. The RT5707 provides eight
programmable output voltage 1.2V to 3.3V while delivering
output current up to 600mA, peak to 1A. The RT5707A
provides eight programmable output voltage 0.7V to 3.1V
while delivering output current up to 400mA, peak to 0.5A.
The Hysteretic Constant-On-Time (HCOT) operation with
internal compensation allow the transient response to be
optimized over a wide range of loads and output capacitors.
The RT5707/A is a available in WL-CSP-8B 0.9x1.6 (BSC)
package.
Ordering Information
Applications
RT5707/A
Package Type
WSC : WL-CSP-8B 0.9x1.6 (BSC)
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
Hand-Held Devices
Portable Information
Battery Powered Equipment
Wearable Devices
Internet of Things
Smart Watch
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Simplified Application Circuit
RT5707/A
VIN
CIN
VIN
L1
SW
VOUT
COUT
VOUT
EN
VSEL1
VIN or GND
VSEL2
VIN or GND
VESL3
VIN or GND
GND
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1
RT5707/A
Marking Information
RT5707WSC
RT5707AWSC
6E : Product Code
6Z : Product Code
W : Date Code
6EW
W : Date Code
6ZW
Pin Configuration
(TOP VIEW)
SW
A1
A2
VIN
EN
B1
B2
GND
VSEL1
C1
C2
VOUT
VSEL2
D1
D2
VSEL3
WL-CSP-8B 0.9x1.6 (BSC)
Functional Pin Description
Pin No.
Pin Name
Pin Function
A1
SW
This pin is the connection between two build-in switches in the chip, which
should be connected to the external inductor. The inductor should be
connected to this pin with the shortest path.
A2
VIN
Supply input. A minimum of 10F (RT5707) and 4.7F (RT5707A) ceramic
capacitor should be connected to this pin with the shortest path
B1
EN
Chip enable input pin. High level voltage enables the device while low level
voltage turns the device off. This pin must be terminated.
B2
GND
Device ground pin. This pin should be connected to input and output
capacitors with the shortest path.
C1
VSEL1
Output voltage selection pin. This pin must be terminated.
C2
VOUT
Output voltage feedback pin. This pin should be connected close to the output
capacitor terminal for better voltage regulation. A minimum of 10F ceramic
capacitor should be connected to this pin with the shortest path.
D1
VSEL2
Output voltage selection pin. This pin must be terminated.
D2
VSEL3
Output voltage selection pin. This pin must be terminated.
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Functional Block Diagram
OSC
OTP
Soft-start
EN
VSEL1
Digital
Control
VSEL2
OCP
VSEL3
UVLO
VIN
Gate
Drive
SW
Fast
Discharge
EN
VOUT
R2
R1
FB
VREF
+
AMP
VREF
GND
PSM/PWM
Control
VOUT
Operation
The RT5707/A is a hysteretic constant on time (HCOT)
switching buck converter. The RT5707/A provides OverTemperature Protection (OTP) and Over-Current Protection
(OCP) mechanisms to prevent the device from damage
with abnormal operations. When the EN voltage is logic
low, the IC will be shut down with low input supply current
less than 1μA.
Enable
The device can be enabled or disabled by the EN pin.
When the EN pin is higher than the threshold of logic-high
IC goes to normal operation. EN pin High transfer Low
into shutdown mode, the converter stops switching, internal
control circuitry is turned off and trigger discharge function.
That discharge function will close after count 10ms (typ.).
If systems need EN toggle operation that EN turn off time
must larger than 100μs for internal circuit reset time.
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
UVLO Protection
To protect the chip from operating at insufficient supply
voltage, the UVLO is needed. When the input voltage is
lower than the UVLO falling threshold voltage, the device
will be lockout.
100% Duty Cycle Operation
The converter enters 100% duty cycle operation once the
input voltage decrease and the difference voltage between
input and output is lower than VTH_100-. The output voltage
follows the input voltage minus the voltage drop across
the internal P_MOSFET and the inductor. Once the input
voltage increases and trips the 100% mode exit threshold,
VTH_100+, the converter backs to normal switching again.
See Figure 1.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3
RT5707/A
VIN
100% duty cycle
100% duty cycle
Over-Current Protection
VOUT
The OCP function is implemented by UGATE and LGATE.
When the inductor current reaches the UGATE current
limit threshold, the high-side MOSFET will be turned-off.
The low-side MOSFET turns on to discharge the inductor
current until the inductor current trips below the LGATE
current limit threshold. After UGATE current limit triggered,
the max inductor current is decided by the inductor current
rising rate and the response delay time of the internal
network.
VIN
VTH_100+
VTH_100VOUT_target
VOUT
VO tracks VIN
Step Down Operation
VO tracks VIN
VUVLO+
VUVLO-
During OCP period, the output voltage drops below the
setting threshold (typ. 0.4V) and the current limit value is
reduced for lowering the devices loss, reducing the heat
and preventing further damage of the chip.
Soft-start
Figure 1. Automatic Transition into 100% Duty Cycle
Over-Temperature Protection
When the junction temperature exceeds the OTP
threshold value, the IC will shut down the switching
operation. Once the junction temperature cools down and
is lower than the OTP lower threshold, the converter will
automatically resume switching.
Output Voltage Selection
The RT5707/A provides 8 level output voltages which can
be programmed via the volatage select pin VSEL1 to
VSEL3. Table 1 indicates the setting to indivdual output
voltage.
Table 1. Output Voltage Setting
Device
RT5707
RT5707A
VOUT (V)
VSEL3
VSEL2
VSEL1
1.2
0
0
0
1.5
0
0
1
1.8
0
1
0
2.1*
0
1
1
2.5
1
0
0
2.8
1
0
1
3
1
1
0
3.3*
1
1
1
0.7
0
0
0
1
0
0
1
1.3
0
1
0
1.6*
0
1
1
1.9
1
0
0
2
1
0
1
2.9
1
1
0
3.1*
1
1
1
* : To series 100k connected to VSEL1 from EN pin.
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
4
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Absolute Maximum Ratings
(Note 1)
VIN, SW, EN, VSEL1, VSEL2, VSEL3, VOUT -------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
WL-CSP-8B 0.9x1.6 (BSC) --------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WL-CSP-8B 0.9x1.6 (BSC), θJA --------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) ----------------------------------------------------------------------------------------------
Recommended Operating Conditions
−0.3V to 6V
0.84W
118.5°C/W
260°C
150°C
−65°C to 150°C
2kV
(Note 4)
Supply Input Voltage -----------------------------------------------------------------------------------------------------RT5707 Output Current (5.5V ≥ VIN ≥ (VOUT_NOM + 0.7V) ≥ 3V) ---------------------------------------------RT5707A Output Current (5.5V ≥ VIN ≥ (VOUT_NOM + 0.7V) ≥ 3V) -------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Ambient Temperature Range --------------------------------------------------------------------------------------------
2.2V to 5.5V
0mA to 600mA
0mA to 400mA
−40°C to 125°C
−40°C to 85°C
Electrical Characteristics
(VIN = 3.6V, CIN = COUT = 10μF, L1 = 2.2μH, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
--
2
2.15
V
--
0.1
0.4
V
BUCK Regulator
Under-Voltage Lockout
Rising Threshold
VUVLOR
Under-Voltage Lockout
Hysteresis
VUVLO_HYS
VIN rising
VOUT_ACC10
VOUT = 1.8V, IOUT = 10mA
2.5
--
2.5
VOUT_ACC100
VOUT = 1.8V, IOUT = 100mA
2
--
2
IQ_Non-SW
VOUT = 1.8V, IOUT = 0A, EN = VIN,
non-switching
--
360
800
IQSW
VOUT = 1.8V, IOUT = 0A, EN = VIN,
switching
--
460
1200
Shutdown Current
ISHDN
EN = GND
--
0.2
1
A
Switching Frequency
f SW
VOUT = 1.8V, CCM mode
--
1.2
--
MHz
UGATE Current Limit
ICL_UG
3V VIN 5.5V
1
1.2
1.4
0.68
0.78
0.88
LGATE Current Limit
ICL_LG
3V VIN 5.5V
1
1.2
1.4
0.55
0.68
0.8
UGATE RON
RON_UG
IOUT = 50mA
--
350
--
m
LGATE RON
RON_LG
IOUT = 50mA
--
250
--
m
VOUT Voltage Accuracy
Input Quiescent Current
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
RT5707
RT5707A
RT5707
RT5707A
%
nA
A
A
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
5
RT5707/A
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Output Discharge Resistor
RDIS
EN = GND, IOUT = 10mA
--
10
--
VOUT Pin Input Leakage
IVOUT
VOUT = 2V, EN = VIN
--
100
--
nA
VOUT Minimum Off Time
tOFF_MIN
--
80
--
ns
VOUT Minimum On Time
tON_MIN
VOUT = 1.8V, VIN = 3.6V
--
420
--
ns
Line Regulation
VOUT_LineReg
VOUT = 1.8V, IOUT = 100mA,
VIN = 2.2V to 5.5V
--
0.1
--
%/V
VOUT_LoadReg1
VOUT = 1.8V, including PFM
operation
--
0.001
--
VOUT_LoadReg2 VOUT = 1.8V, only CCM operation
--
0.0005
--
Over-Temperature
Protection
TOTP
--
150
--
°C
Over-Temperature
Protection Hysteresis
TOTP_HYS
--
20
--
°C
Auto 100% Duty Cycle
Leave Detection Threshold
VTH_100+
Rising VIN, 100% mode is left with
VIN = VOUT + VTH_100+
150
250
350
mV
Auto 100% Duty Cycle
Enter Detection Threshold
VTH_100-
Falling VIN, 100% mode is entered
with VIN = VOUT + VTH_100-
85
200
290
mV
Regulator Start Up Delay
Time
tSS_EN
IOUT = 0mA, EN = GND to VIN,
VOUT starts rising
--
0.1
--
ms
Regulator Soft Start Time
tSS
VOUT = 1.8V, IOUT = 10mA,
EN = VIN
--
0.7
--
ms
Load Regulation
%/mA
Timing
Logic Input (EN, VSEL1, VSEL2 and VSEL3)
Input High Threshold
VIH
VIN = 2.2V to 5.5V
1.2
--
--
V
Input Low Threshold
VIL
VIN = 2.2V to 5.5V
--
--
0.4
V
Input Pin Bias Current
IIN
--
10
--
nA
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured under natural convection (still air) at TA = 25°C with the component mounted on a high effectivethermal-conductivity four-layer test board on a JEDEC 51-7 thermal measurement standard.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
6
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Typical Application Circuit
For the RT5707
VIN
2.2V to 5.5V
A2
CIN
10µF
B1
C1
VIN or GND
D1
VIN or GND
D2
VIN or GND
RT5707
VIN
SW
VOUT
L1
2.2µH
A1
COUT
10µF
C2
Main
System
EN
VSEL1
VSEL2
VSEL3
GND
B2
Recommended components information for the RT5707 as below table :
Reference
Part Number
Description
Package
Manufacturer
CIN, COUT
GRM155R60J106ME15
10F/6.3V/X5R
0402
Murata
L1
1239AS-H-2R2M
2.2H
2520
Murata
For the RT5707A
VIN
2.2V to 5.5V
A2
VIN
SW
CIN
4.7µF
B1
C1
VIN or GND
D1
VIN or GND
D2
VIN or GND
L1
2.2µH
RT5707A
VOUT
A1
COUT
10µF
C2
Main
System
EN
VSEL1
VSEL2
VSEL3
GND
B2
Recommended components information for the RT5707A as below table :
Reference
Part Number
Description
Package
Manufacturer
CIN
GRM155R60J475ME47
4.7F/6.3V/X5R
0402
Murata
COUT
GRM155R60J106ME15
10F/6.3V/X5R
0402
Murata
L1
DFE201610E-2R2M=P2
2.2H
2016
Murata
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
7
RT5707/A
Typical Operating Characteristics
Efficiency vs. Load Current
100
95
90
90
Efficiency (%)
Efficiency (%)
Efficiency vs. Load Current
100
VIN = 3.6V
VIN = 4.2V
VIN = 5V
85
80
75
80
70
VIN = 2.5V
VIN = 3V
VIN = 3.6V
60
50
70
40
VOUT = 3.3V
65
0.001
0.01
0.1
1
10
100
VOUT = 0.7V
30
0.001
1000
0.01
0.1
Load Current (mA)
1000
70
1.8
VIN = 5V
VIN = 4.2V
VIN = 3.8V
1.6
Output Voltage Ripple (mVpp)
Switching Frequency (MHz)1
100
Output Voltage Ripple
Switching Frequency vs. Load Current
1.4
1.2
1.0
0.8
0.6
0.4
0.2
VOUT = 3.3V
0.0
0
100
200
300
400
500
60
50
40
30
VIN = 5.5V
VIN = 5V
VIN = 4.2V
20
10
VOUT = 3.3V
0
0.001
600
0.01
0.1
1
10
100
1000
Load Current (mA)
Load Current (mA)
Quiescent Current
Output Voltage Ripple
1.0
22.5
VOUT = 0.7V
20.0
VIN = 2.5V
VIN = 3V
VIN = 3.6V
15.0
12.5
10.0
7.5
0.001
0.9
0.8
0.7
Switching
0.6
0.5
Non-switching
0.4
0.3
0.01
0.1
1
10
100
Load Current (mA)
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
8
VOUT = 3.3V
Quiescent Current (μA)
Output Voltage Ripple (mVpp)
10
Load Current (mA)
2.0
17.5
1
1000
3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
5.1
5.3
5.5
Input Voltage (V)
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Quiescent Current
1.0
1.0
0.9
Shutdown Current (μA)1
0.9
Quiescent Current (μA)
Shutdown Current
0.8
0.7
0.6
Switching
0.5
0.4
Non-switching
0.3
0.2
0.1
VOUT = 1.8V
0.0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2.2 2.5 2.8 3.1 3.4 3.7 4.0 4.3 4.6 4.9 5.2 5.5
2.2 2.5 2.8 3.1 3.4 3.7 4.0 4.3 4.6 4.9 5.2 5.5
Input Voltage(V)
Input Voltage (V)
PSM Mode Operation
VOUT_AC
(50mV/Div)
PWM Mode Operation
VOUT_AC
(50mV/Div)
VSW
(5V/Div)
VSW
(5V/Div)
VIN = 5V, VOUT = 3.3V, IOUT = 300mA
VIN = 5V, VOUT = 3.3V, IOUT = 50mA
IL
(200mA/Div)
IL
(200mA/Div)
Time (4μs/Div)
Time (400ns/Div)
Power On with Resistor Load
Power On with Resistor Load
VOUT
(2V/Div)
VOUT
(2V/Div)
VEN
(5V/Div)
VEN
(5V/Div)
VIN = 5V, VOUT = 3.3V, IOUT
about = 100mA (EN enable)
IL
(500mA/Div)
IL
(500mA/Div)
Time (400μs/Div)
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
VIN = 3.6V, VOUT = 3.3V, IOUT
about = 300mA (EN enable)
September 2020
Time (400μs/Div)
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
9
RT5707/A
Load Transient Response
Load Transient Response
VIN = 5V, VOUT = 3.3V,
IOUT 100mA to 290mA,
TR = TF = 1μs
VIN = 5V, VOUT = 3.3V,
IOUT 5mA to 290mA,
TR = TF = 1μs
VOUT_AC
(50mV/Div)
VOUT_AC
(50mV/Div)
IL
(100mA/Div)
IL
(100mA/Div)
VOUT_AC
(50mV/Div)
Time (200μs/Div)
Time (200μs/Div)
Load Transient Response
Load Transient Response
VIN = 5V, VOUT = 3.3V,
IOUT 50mA to 500mA,
TR = TF = 1.6μs
VIN = 5V, VOUT = 3.3V,
IOUT 50mA to 450mA,
TR = TF = 1μs
VOUT_AC
(50mV/Div)
IL
(200mA/Div)
IL
(200mA/Div)
Time (200μs/Div)
Time (200μs/Div)
100% Duty Cycle Entry and Leave Operation
VOUT
(500mV/Div)
VIN = 2.2V to 5.5V (Ramp rise),
VOUT = 3.3V, IOUT = 30mA
VIN
(2V/Div)
IL
(200mA/Div)
Time (20ms/Div)
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
10
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Application Information
The RT5707/A is a synchronous low voltage step-down
converter that can support the input voltage range from
2.2V to 5.5V and the output current can be up to 600mA,
peak to 1A (RT5707) / 400mA, peak to 0.5A (RT5707A).
Internal compensation are integrated to minimize external
component count. Protection features include over-current
protection, under-voltage protection and over-temperature
protection.
Inductor Selection
The recommended power inductor is 2.2μH and inductor
saturation current rating choose follow over current
protection design consideration. In applications, it needs
to select an inductor with the low DCR to provide good
performance and efficiency.
CIN and COUT Selection
The input capacitance, C IN, is needed to filter the
trapezoidal current at the source of the top MOSFET. To
prevent large ripple voltage, a low ESR input capacitor
sized for the maximum RMS current should be used. RMS
current is given by :
V
VIN
IRMS = IOUT(MAX) OUT
1
VIN
VOUT
This formula has a maximum at VIN = 2VOUT, where IRMS =
IOUT / 2. This simple worst-case condition is commonly
used for design because even significant deviations do
not offer much relief. To choose a capacitor rated at a
higher temperature than required.
Several capacitors may also be paralleled to meet size or
height requirements in the design.
Thermal Considerations
The junction temperature should never exceed the
absolute maximum junction temperature TJ(MAX), listed
under Absolute Maximum Ratings, to avoid permanent
damage to the device. The maximum allowable power
dissipation depends on the thermal resistance of the IC
package, the PCB layout, the rate of surrounding airflow,
and the difference between the junction and ambient
temperatures. The maximum power dissipation can be
calculated using the following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction-to-ambient
thermal resistance.
For continuous operation, the maximum operating junction
temperature indicated under Recommended Operating
Conditions is 125°C. The junction-to-ambient thermal
resistance, θJA, is highly package dependent. For a WLCSP-8B 0.9x1.6 (BSC) package, the thermal resistance,
θJA, is 118.5°C/W on a standard JEDEC 51-7 high effectivethermal-conductivity four-layer test board. The maximum
power dissipation at TA = 25°C can be calculated as below
PD(MAX) = (125°C − 25°C) / (118.5°C/W) = 0.84W for a
WL-CSP-8B 0.9x1.6 (BSC) package.
The maximum power dissipation depends on the operating
ambient temperature for the fixed TJ(MAX) and the thermal
resistance, θJA. The derating curves in Figure 2 allows
the designer to see the effect of rising ambient temperature
on the maximum power dissipation.
The selection of COUT is determined by the Effective Series
Resistance (ESR) that is required to minimize voltage ripple
and load step transients, as well as the amount of bulk
capacitance that is necessary to ensure that the control
loop is stable. Loop stability can be checked by viewing
the load transient response as described in a later section.
The output ripple, ΔVOUT, is determined by :
1
VOUT IL ESR +
8
f
C
SW
OUT
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
11
RT5707/A
Maximum Power Dissipation (W)1
1.0
Four-Layer PCB
0.9
Layout Considerations
For high frequency switching power supplies, the PCB
layout is important to get good regulation, high efficiency
and stability. The following descriptions are the guidelines
for better PCB layout.
0.8
0.7
0.6
0.5
For
good regulation, place the power components as
close as possible. The traces should be wide and short
enough especially for the high-current loop.
0.4
0.3
0.2
Shorten
0.1
the SW node trace length and make it wide.
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 2. Derating Curve of Maximum Power Dissipation
Table 2. Protection Trigger Condition and Behavior
Threshold Refer to
Electrical Spec.
Protection Method
Reset Method
UGATE Current Limit
ISW > 1.2A (Typ.)
Turn off UG MOS
ISW < 1.2A (Typ.)
LGATE Current Limit
ISW > 1.2A (Typ.)
Turn on LG MOS
ISW < 1.2A (Typ.)
UGATE Current Limit
ISW > 0.78A (Typ.)
Turn off UG MOS
ISW < 0.78A (Typ.)
LGATE Current Limit
ISW > 0.68A (Typ.)
Turn on LG MOS
ISW < 0.68A (Typ.)
UVLO
VUVLOF < 1.9V (Typ.)
Shutdown
VUVLOR > 2V (Typ.)
OTP
Temperature > 150°C (Typ.)
Shutdown
Temperature < 130°C (Typ.)
Protection Type
RT5707
RT5707A
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
12
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
TOP View
The inductor should be connected
to this pin with the shortest path.
VIN
L1
CIN
SW
VIN
EN
GND
VSEL1
VOUT
VSEL2
VSEL3
VOUT
VIN
The input capacitor Cin connected to
this pin should be grounded with the
shortest path
COUT
The output capacitor COUT connected to
this pin should be grounded with the
shortest path
The VSEL1, VSEL2, VSEL3 and EN pin
should be connected to MCU or GND.
Do not floating these pins.
Figure 3. RT5707 PCB Layout Guide
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
13
RT5707/A
TOP View
VIN
The inductor should be connected
to this pin with the shortest path.
CIN
L1
SW
VIN
EN
GND
VSEL1
VOUT
VSEL2
VSEL3
VOUT
VIN
The input capacitor Cin connected to
this pin should be grounded with the
shortest path
COUT
The output capacitor COUT connected to
this pin should be grounded with the
shortest path
The VSEL1, VSEL2, VSEL3 and EN pin
should be connected to MCU or GND.
Do not floating these pins.
Figure 4. RT5707A PCB Layout Guide
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
www.richtek.com
14
is a registered trademark of Richtek Technology Corporation.
DS5707/A-04
September 2020
RT5707/A
Outline Dimension
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.500
0.600
0.020
0.024
A1
0.170
0.230
0.007
0.009
b
0.240
0.300
0.009
0.012
D
1.560
1.640
0.061
0.065
D1
E
1.200
0.860
0.047
0.940
0.034
0.037
E1
0.400
0.016
e
0.400
0.016
8B WL-CSP 0.9x1.6 Package (BSC)
Copyright © 2020 Richtek Technology Corporation. All rights reserved.
DS5707/A-04
September 2020
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
15
RT5707/A
Footprint Information
Package
Number of
Pin
WL-CSP0.9x1.6-8(BSC)
8
Type
NSMD
SMD
Footprint Dimension (mm)
e
0.400
A
B
0.240
0.340
0.270
0.240
Tolerance
±0.025
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
www.richtek.com
16
DS5707/A-04
September 2020
工商网监
湘ICP备2023018690号
