R1214Z Series
PWM/ VFM Step-up DC/DC Converter for White LED Applications
NO.EA-327-170919
OUTLINE
The R1214Z is a low supply current PWM/ VFM step-up DC/DC converter. Internally, the device consists of an
Nch MOSFET driver, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier, an
overcurrent protection circuit, an under voltage lockout circuit (UVLO), an overvoltage protection circuit (LXOVP,
LEDOVP), a thermal shutdown protection circuit and 2-channel current drivers for white LEDs.
The R1214Z requires minimal external component count. By simply using an inductor, a resistor, capacitors
and a diode, the white LEDs can be driven with constant current and high efficiency. The LED current can be
determined by the value of current setting resistor. The brightness of the LEDs can be adjusted quickly by
applying a 200 Hz to 300 kHz PWM signal to the PWM pin.
The R1214Z provides the PWM control or the PWM/VFM auto switching control. The PWM control switches
at fixed frequency rate in low output current in order to reduce noise. Likewise, the PWM/VFM auto switching
control automatically switches from PWM mode to VFM mode in low output current in order to achieve high
efficiency. RICOH’s unique control method can suppress a ripple voltage in the VFM mode, thus the R1214Z
can achieve both low ripple voltage at light load and high efficiency.
The R1214Z provides an overcurrent protection circuit to limit the Lx peak current, an UVLO circuit to prevent
the malfunction of the device at low input voltage, a LXOVP circuit to monitor the excess LX voltage, a LEDOVP
circuit to monitor the excess LED1-2 voltage and a thermal shutdown protection circuit to detect the
overheating of the device and stops the operation to protect the device from damage.
The R1214Z is offered in a 9-pin WLCSP-9-P1 package.
FEATURES
Input Voltage Range (Maximum Rating) ············· 2.7 V to 5.5 V (6.5 V)
Supply Current ············································· Typ. 500 µA
Standby Current ············································ Typ. 0.2 µA, Max. 5 µA
Overcurrent Protection Circuit ·························· Typ. 1.9 A
Overvoltage Protection (OVP) Circuit ················· Typ. 35 V
LED1-2 Current Matching Circuit ······················ Max. 0.5% (R1214Zxx1C/ D, 20 mA)
Max. 1.0% (R1214Zxx1A/ B, 20 mA)
Oscillator Frequency ······································ Typ. 750 kHz/ 450 kHz
Maximum Duty Cycle ····································· Typ. 96% (R1214Zx11x)
Typ. 94% (R1214Zx21x)
Nch ON Resistance ······································· Typ. 0.25 Ω (VIN = 3.6 V)
Undervoltage Lockout (UVLO) Circuit ················ Typ. 2.4 V
Thermal Shutdown Circuit ······························· Typ. 150°C
LED Dimming Control····································· By sending a 200 Hz to 300 kHz PWM signal to the PWM pin
Package ······················································ WLCSP-9-P1
1
R1214Z
NO.EA-327-170919
APPLICATION
White LED backlight driver for LCD displays for portable equipment
White LED backlight driver for LCD displays for Smartphones, Tablets and Note PCs
SELECTION GUIDE
The combinations of oscillator frequency, LED voltage and power controlling method are user-selectable
options.
Selection Guide
Product Name
Package
R1214Z2(y)1(z)-E2-F
WLCSP-9-P1
2(y)1(z)
2
(y): Oscillator
Frequency
211A
450 kHz
221A
750 kHz
211B
450 kHz
211C
450 kHz
221C
750 kHz
211D
450 kHz
Quantity per Reel
5,000 pcs
(z): LED Voltage
(ILED = 20 mA)
Pb Free
Halogen Free
Yes
Yes
(z): Power Controlling Method
320 mV
PWM/ VFM Auto Switching
320 mV
PWM
600 mV
PWM/ VFM Auto Switching
600 mV
PWM
R1214Z
NO.EA-327-170919
BLOCK DIAGRAMS
R1214Z Block Diagram
LX
OVP
UVLO
Ramp
Compensation
Current
Feedback
VIN
Current
Limit
LX
Switching
Control
Vref
COMP
LED
OVP
LED
Feedback
Selector
Max
Duty
Thermal
Shutdown
GND
LED1
LED Current Source
PWM
ISET
Current
Control
Soft
Start
LED2
CE
Chip
Enable
LED Current Source
3
R1214Z
NO.EA-327-170919
PIN DESCRIPTION
Top View
A
B
Bottom View
C
C
3
3
2
2
1
B
A
1
WLCSP-9-P1 Pin Configurations
WLCSP-9-P1 Pin Description
4
Pin No.
Symbol
Description
A1
ISET
LED Current Control Pin
A2
LED1
LED Current Supply Pin 1
A3
LED2
LED Current Supply Pin 2
B1
PWM
PWM Dimming Control Input Pin
B2
COMP
Error Amplifier Output Pin
B3
GND
C1
CE
Chip Enable Pin, Active-high
C2
VIN
Analog Input Voltage Pin
C3
LX
Switching Pin, Open Drain Output
Ground Pin
R1214Z
NO.EA-327-170919
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings
(GND = 0 V)
Symbol
Item
Rating
Unit
VIN
VIN Pin Voltage
−0.3 to 6.5
V
VCE
CE Pin Voltage
−0.3 to 6.5
V
VISET
ISET Pin Voltage
−0.3 to 6.5
V
VCOMP
COMP Pin Voltage
−0.3 to 6.5
V
LX Pin Voltage(1)
−0.3 to 41.5
V
VPWM
PWM Pin Voltage
−0.3 to 6.5
V
VLED
LED1, LED2 Pin Voltage
−0.3 to 6.5
V
1190
mW
VLX
PD
Power Dissipation (High Wattage Land Pattern) (2)
Tj
Junction Temperature Range
−40 to 125
°C
Tstg
Storage Temperature Range
−55 to 125
°C
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the permanent
damages and may degrade the life time and safety for both device and system using the device in the field.
The functional operation at or over these absolute maximum ratings are not assured.
RECOMMENDED OPERATING CONDITONS
Symbol
Item
Rating
Unit
VIN
Input Voltage
2.7 to 5.5
V
Ta
Operating Temperature Range
−40 to 85
C
RECOMMENDED OPERATING CONDITIONS
All of electronic equipment should be designed that the mounted semiconductor devices operate within the
recommended operating conditions. The semiconductor devices cannot operate normally over the recommended
operating conditions, even if when they are used over such ratings by momentary electronic noise or surge. And the
semiconductor devices may receive serious damage when they continue to operate over the recommended
operating conditions.
(1)
Constantly applying a constant-voltage higher than 6.5 V to the LX pin from the outside may cause the permanent
damages to the device.
(2)
Refer to POWER DISSIPATION for detailed information.
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R1214Z
NO.EA-327-170919
ELECTRICAL CHARACTERISTICS
The specifications surrounded by
are over −40°C ≤ Ta ≤ 85°C.and guaranteed by design engineering.
R1214Z Electrical Characteristics
Symbol
IDD
Item
Supply Current
Istandby Standby Current
Conditions
Min.
Typ.
VIN = 3.6 V, no load, non-switching
0.5
VIN = 5.5 V, VCE = 0 V
0.2
Unit
mA
5.0
VIN falling
VUVLO2
UVLO Released Voltage
VIN rising
VCEH
CE Input Voltage "H"
VIN = 5.5 V
VCEL
CE Input Voltage "L"
VIN = 2.7 V
RCE
CE Pull-down Resistance
VIN = 5.5 V
1200
KΩ
PWM Pull-down Resistance
VIN = 5.5 V
1200
KΩ
ILEDM1
ILEDM2
ILEDMAX
RISET = 30.1 kΩ
(1 string = 20 mA)
VIN = 3.6 V
RISET = 30.1 kΩ
LED1-2 Current Matching
PWMduty = 100%
Accuracy 1 (1 string = 20 mA) VIN = 3.6 V
(IMAX − IAve (3)) / IAve
RISET = 30.1 kΩ
PWMduty = 10%
LED1-2 Current Matching
(fPWM = 20 kHz)
Accuracy 2 (1 string = 20 mA)
VIN = 3.6 V
(IMAX − IAve) / IAve
LED1-2 Maximum Current at
VIN = 3.6 V
100% Dimming Range
LED1-2 Current Accuracy
ILEDLEAK LED1-2 Leakage Current
VUVLO1
+0.1
19.6
20
20.4
R1214Zxx1C/ D
19.7
20
20.3
R1214Zxx1A/ B
0.2
1.0
R1214Zxx1C/ D
0.1
0.5
R1214Zxx1A/ B
0.5
R1214Zxx1C/ D
0.3
Lx Leakage Current
VIN = 5.5 V, VLX = 41 V
ILXLIM
Lx Current Limit
VIN = 3.6 V
LED1-2 Regulated Voltage
R1214Zxx1A/ B (1 string = 20 mA),
VIN = 3.6 V
R1214Zxx1C/ D (1 string = 20 mA),
VIN = 3.6 V
(3)
IAve is the average current of LED1-2.
mA
%
mA
3.0
1.9
µA
Ω
0.25
1.3
V
%
40
VIN = 5.5 V, VLED1-2 = 1 V, VCE = 0 V
ILXLEAK
V
V
R1214Zxx1A/ B
VIN = 3.6 V, ILX = 100 mA
Oscillator Frequency
2.65
0.4
Nch ON Resistance
fosc
V
1.5
RON
VLED
2.4
µA
UVLO Detector Threshold
ILED
2.25
Max.
VUVLO1
RPWM
6
(Ta = 25°C)
3.0
µA
2.5
A
320
mV
600
R1214Zx11x, VIN = 3.6 V
400
450
500
R1214Zx21x, VIN = 3.6 V
675
750
825
kHz
R1214Z
NO.EA-327-170919
ELECTRICAL CHARACTERISTICS (continued)
The specifications surrounded by
are over −40°C ≤ Ta ≤ 85°C.and guaranteed by design engineering.
R1214Z Electrical Characteristics
Symbol
Item
Maxduty Maximum Duty Cycle
(Ta = 25°C)
Conditions
Min.
Typ.
R1214Zx11x, VIN = 3.6 V
92
96
R1214Zx21x, VIN = 3.6 V
91
94
VOUT rising
VIN = 3.6 V
29
35
41
V
4.3
4.5
4.7
V
R1214Z2x1x
VOVP1
VLX OVP Detector Threshold
VOVP2
VLED OVP Detector Threshold VLED1-2 rising, VIN = 3.6 V
tstart
Soft Start Time
TTSD
TTSR
Thermal Shutdown
Temperature
Thermal Shutdown
Release Temperature
Max.
Unit
%
VIN = 3.6 V
15
ms
VIN = 3.6 V
150
°C
VIN = 3.6 V
125
°C
All test items listed under ELECTRICAL CHARACTERISTICS are done under the pulse load condition (Tj ≈ Ta = 25°C)
except LED1-2 Current max at 100% Dimming Range.
7
R1214Z
NO.EA-327-170919
THEORY OF OPERATION
Soft-Start
During start-up, soft-start increases the output voltage (VOUT) by forcibly switching the LX pin and gradually
increasing the LX current limit (ILXLIM). If the preset LED current is 1.5 mA or more, soft-start gradually increases
the LED current (ILED) until it reaches the preset LED current. If the preset LED current is less than 1.5 mA,
soft-start increases ILED until it reaches 1.5 mA, then reduces it to the preset LED current. To minimize the
overshoot of ILED, a 1-µF capacitor (C4) can be used.
Overcurrent Protection
If the peak inductor current (ILmax) exceeds ILXLIM, overcurrent protection turns the driver off and turns it on in
every switching cycle to continually monitor the driver current.
Overvoltage Protection (OVP)
The flow chart below illustrates the functions of LxOVP and LEDOVP. LxOVP protects the device from high
voltage due to the disconnection of white LED string. To release the latch-type LxOVP or LEDOVP, set the CE
pin low or decrease the VIN pin voltage below the UVLO detector threshold.
LxOVP and LEDOVP Function Flow
Under Voltage Lockout (UVLO)
UVLO stops the device operation to prevent malfunction when the input (VIN) voltage falls below the UVLO
detector threshold.
8
R1214Z
NO.EA-327-170919
Thermal Shutdown
Thermal shutdown circuit detects overheating of the converter and stops the device operation to protect it from
damage. If the junction temperature of the device exceeds the specified temperature, the thermal shutdown
stops the device operation and resumes the device operation if the junction temperature decreases below the
thermal shutdown release temperature.
Input Signal Sequencing
The timing of turning on or off of LEDs can be controlled by sequencing the input signals. There are two ways
of sequencing the input signals:
Sequencing 1. Send a signal to the PWM pin first and then switch the CE pin to high.
The device shifts from standby mode to active mode to turn the LEDs on.
Sequencing 1 Diagarm
Sequencing 2. Send a signal to the PWM pin while the CE pin is constantly set high.
The device shifts from standby mode to active mode to turn the LEDs on. If a signal is not sent to the PWM
pin more than 50 ms (Max.), the device shifts from active mode to standby mode to turn the LEDs off.
Standby
Standby
Active
Constantly H
Max 50ms
CE
PWM
time
Sequencing 2 Diagarm
9
R1214Z
NO.EA-327-170919
LED Dimming Control
The brightness of the LEDs can be adjusted by applying a PWM signal to the PWM pin. The LED current (ILED)
can be controlled by the duty of a PWM signal for the PWM pin. The duty range of a PWM signal can be set
in a range of 0.4% to 100% when using a 1-µF capacitor (C4) and a 30.1-kΩ feedback resistor (RISET). The
relation between the high-duty of the PWM pin (Hduty) and ILED can be calculated as follows:
ILED = Hduty x ILEDSET
The frequency of a PWM signal for dimming the LEDs can be set within the range of 200 Hz to 300 kHz;
however, it is recommended that a 20-kHz to 100-kHz frequency be used. In the case of using a less than 20kHz PWM signal, an increase or decrease in an inductor current (IL) may generate noise in the audible band.
To avoid this, connect a 2.2-µF or more capacitor (C3) between the ISET pin and GND pin. In the case of using
a 20-kHz or more PWM signal, C3 is not required. Note that if a PWM signal is changed stepwise, a change
in the LED luminance level can be visible as shown in the following figure. To reduce the visible change in the
LED luminance level, C3 can also be used.
Reducing the visible change in LED luminance level by using C3
ILED
ILED
PWM
C3 = 0 µF
PWM
C3 = 2.2 µF
White LED Current Setting
The LED current for each LED string when a PWM signal applied to the PWM pin is Duty = 100% (ILEDSET) can
be determined by the value of feedback resistor (RISET). ILEDSET can be calculated as follows:
ILEDSET = 0.0466 x RISET / (40 k + RISET)
RISET should be set to 19 kΩ or more. If RISET with 30.1 kΩ is placed between the ISET and GND pins, ILEDSET
will be set to 20 mA.
10
R1214Z
NO.EA-327-170919
Operation of Step-Up Dc/Dc Converter And Output Current
IL2
IOUT
VOUT
Diode
L
VIN
IL1
Nch Tr.
CL
GND
Basic Circuit
Inductor Current (IL) Waveform
IL
ILmax
IL
ILmax
ILmin
ILmin
topen
t
ton
toff
T=1/fosc
Discontinuous Inductor Current Mode
Iconst
t
ton
toff
T=1/fosc
Continuous Inductor Current Mode
The PWM control type of the step-up DC/DC converter has two operation modes characterized by the
continuity of inductor current: discontinuous inductor current mode and continuous inductor current mode.
When an Nch transistor is in On-state, the voltage to be applied to the inductor (L) is described as VIN. An
increase in the inductor current (IL1) can be written as follows:
IL1 = VIN x ton / L ........................................................................................................................... Equation 1
In the step-up DC/DC converter circuit, the energy accumulated during the On-state is transferred into the
capacitor even in the Off-state. A decrease in the inductor current (IL2) can be written as follows:
IL2 = (VOUT − VIN) x topen / L ............................................................................................................ Equation 2
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R1214Z
NO.EA-327-170919
In the PWM control, IL1 and IL2 become continuous when topen = toff, which is called continuous inductor
current mode.
When the device is in continuous inductor current mode and operates in steady-state conditions, the variations
of IL1 and IL2 are same:
VIN x ton / L = (VOUT - VIN) x toff / L .................................................................................................... Equation 3
Therefore, the duty cycle in continuous inductor current mode is:
duty (%)= ton / (ton + toff) = (VOUT − VIN) / VOUT................................................................................ Equation 4
When topen = toff, the average of IL1 is:
IL1 (Ave.) = VIN x ton / (2 x L) ........................................................................................................... Equation 5
If the input voltage (VIN) is equal to the output voltage (VOUT), the output current (IOUT) is:
IOUT = VIN2 x ton / (2 x L x VOUT)......................................................................................................... Equation 6
If IOUT is larger than Equation 6, the device switches to continuous inductor current mode
The peak inductor current (ILmax) is:
ILmax = IOUT x VOUT / VIN + VIN x ton / (2 x L ) .................................................................................. Equation 7
ILmax = IOUT x VOUT / VIN + VIN x T x (VOUT − VIN) / (2 x L x VOUT) ...................................................... Equation 8
As a result, ILmax becomes larger compared to IOUT. The overcurrent protection circuit operates if the ILmax
becomes more than the LX current limit. When considering the input and output conditions or selecting the
external components, please pay attention to ILmax.
Notes: The above calculations are based on the ideal operation of the device. They do not include the losses
caused by the external components or Nch transistor. The actual maximum output current will be 50% to 80%
of the above calculation results. Especially, if IL is large or VIN is low, it may cause the switching losses. An
approximately 0.8 V forward voltage (VF) of diode should be added to VOUT in the above calculations.
12
R1214Z
NO.EA-327-170919
APPLICATION INFORMATION
Typical Application Circuits
VIN = 2.7 V to 5.5 V
VIN
LED1
ISET
LED2
RISET
C3
R1214Z
GND
COMP
8 LEDs x 2 Parallels
C4
CE
VOUT
LX
PWM
D1
PWM = 200 Hz to 20 kHz
C2
L1
C1
Typical Application: 8 LEDs in series x 2 parallels, 200 Hz to 20 kHz PWM signal
VIN = 2.7 V to 5.5 V
VIN
LED1
ISET
LED2
RISET
R1214Z
GND
COMP
8 LEDs x 2 Parallels
C4
CE
VOUT
LX
PWM
D1
PWM = 20 kHz to 300 kHz
L1
C2
C1
Typical Application: 8 LEDs in series x 2 parallels, 20 kHz to 300 kHz PWM signal
13
R1214Z
NO.EA-327-170919
Recommended Inductors
L1 (µH)
Product Name
10
10
10
R1214Z221x
(750 kHz)
10
22
22
R1214Z211x
(450 kHz)
22
Rated Current
Inductor Size
(mA)
(mm)
550
2.5 x 2.0 x 1.0
VLS252010ET-100M
620
3.0 x 2.5 x 1.2
VLF302512MT-100M
900
4.0 x 3.2 x 1.2
VLF403212MT-100M
1320
5.0 x 4.0 x 1.2
VLF504012MT-100M
430
3.0 x 2.5 x 1.2
VLF302512MT-220M
540
4.0 x 3.2 x 1.2
VLF403212MT-220M
890
5.0 x 4.0 x 1.2
VLF504012MT-220M
Components No.
Recommended Components
Symbol
Description
Rated Voltage (V)
Value
Components No.
C1 (CIN)
Ceramic Capacitor
6.3
4.7 µF or more
C1608JB0J475K
2.2 µF or more
R1214Z211x
C2 (COUT)
Ceramic Capacitor
C2012X5R1H225K
50
1.0 µF or more
R1214Z221x
C2012X5R1H105K
C3
Ceramic Capacitor
6.3
2.2 µF or more
-
C4
Ceramic Capacitor
6.3
0.1 µF to 1µF
-
60
-
CRS12
D1
Diode
60
-
RB060M-60
Cautions in Selecting External Components
Selection of Inductor
The peak inductor current (ILmax) under steady operation can be calculated as follows:
ILmax = 1.25 x ILED x VOUT / VIN + 0.5 x VIN x (VOUT − VIN) / (L x VOUT x fosc)
When starting up the device or adjusting the brightness of LED lights using the PWM pin, a large transient
current may flow into an inductor (L1). ILmax should be equal or smaller than the Lx current limit (ILXLIM) of the
device. It is recommended that a 10 µH to 22 µH inductor be used.
14
R1214Z
NO.EA-327-170919
Selection of Capacitor
Set a 4.7 µF or more input capacitor (C1) between the VIN and GND pins as close as possible to the pins.
Set a 2.2 µF or more output capacitor (C2) between the VOUT and GND pins for R1214Zx11x.
Set a 1 µF or more output capacitor (C2) between the VOUT and GND pins for R1214Zx21x.
If a PWM input signal is within the range of 200 Hz to 20 kHz, set a 2.2 µF or more capacitor (C3) between the
ISET and GND pins. If a PWM input signal is within the range of 20 kHz to 300 kHz, a capacitor (C3) is not
required. Set a capacitor (C4) 0.1 µF between the COMP and GND pins.
Selection of SBD (Schottky Barrier Diode)
Choose a diode that has low forward voltage (VF), low reverse current (IR), and low parasitic capacitance.
SBD is an ideal type of diode for R1214Z since it has low VF, low IR, and low parasitic capacitance.
TECHNICAL NOTES
The performance of a power source circuit using this device is highly dependent on a peripheral circuit. A
peripheral component or the device mounted on PCB should not exceed a rated voltage, a rated current or a
rated power. When designing a peripheral circuit, please be fully aware of the following points.
Place an input capacitor (C1) between the VIN pin and the GND pin as close as possible. Also, connect
the GND pin to the wider plane.
Make the LX land pattern as small as possible.
Make the wirings between the LX pin, the inductor and the diode as short as possible. Also, connect an
output capacitor (C2) as close as possible to the cathode of the diode.
Place C2 as close as possible to the GND pin.
Unused LED pin should be connected to GND.
Figure 1 and Figure 2 show the current pathways of application circuits when MOSFET is turned ON or
when MOSFET is turned OFF, respectively. As shown in Figure 1 and Figure 2, the currents flow in the
directions of blue or green arrows. The parasitic components, such as impedance, inductance or
capacitance, formed in the pathways indicated by the red arrows affect the stability of the system and
become the cause of noise. Reduce the parasitic components as much as possible. The current pathways
should be made by short and thick wirings.
Load
Load
Figure 1. MOSFET-ON
Figure 2. MOSFET-OFF
15
R1214Z
NO.EA-327-170919
Reference PCB Layouts
R1214Z (WLCSP-9-P1) PCB Layout
16
R1214Z
NO.EA-327-170919
TYPICAL CHARACTERISTICS
Note: Typical Characteristics are intended to be used as reference data; they are not guaranteed.
1) Efficiency vs. Output Current
1-1) Efficiency of R1214Z211A with Different Input Voltages
VLF403012-100M/ 6s2p LEDs
VLF403012-220M/ 6s2p LEDs
(VOUT = 16.9 V at 40 mA per 1 String)
(VOUT = 16.9 V at 40 mA per 1 String)
VLF403012-100M/ 8s2p LEDs
(VOUT = 22.3 V at 40 mA per 1 String)
VLF403012-220M/ 8s2p LEDs
(VOUT = 22.3 V at 40 mA per 1 String)
1-2) Efficiency of R1214Z211A with Different Inductors (VOUT = 28 V at 80 mA)
VIN = 3.6 V/ 6s2p LEDs
VIN = 3.6 V/ 6s2p LEDs
(VOUT = 16.9 V at 40 mA per 1 String)
(VOUT = 16.9 V at 40 mA per 1 String)
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R1214Z
NO.EA-327-170919
VIN = 3.6 V/ 8s2p LEDs
(VOUT = 22.3 V at 40 mA per 1 String)
VIN = 3.6 V/ 8s2p LEDs
(VOUT = 22.3 V at 40 mA per 1 String)
2) PWM Dimming Duty vs. ILED (RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
(fPWM = 20 kHz)
(RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
(fPWM = 20 kHz)
(RISET = 30.1 kΩ)
3) ILED Waveform in the VFM Mode
VIN = 3.6 V/ 8s2p LEDs
R1214Z211A (fPWM = 10 kHz, PWMduty = 10%)
(RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
R1214Z221A (fPWM = 10 kHz, PWMduty = 10%)
(RISET = 30.1 kΩ)
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NO.EA-327-170919
4) Startup/ Shutdown Waveform
VIN = 3.6 V/ 8s2p LEDs
R1214Zxxxx (fPWM = 20 kHz, PWMduty = 50%)
(RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
R1214Zxxxx (fPWM = 20 kHz, PWMduty = 50%)
(RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
R1214Zxxxx (fPWM = 20 kHz, PWMduty = 100%)
(RISET = 30.1 kΩ)
VIN = 3.6 V/ 8s2p LEDs
R1214Zxxxx (fPWM = 20 kHz, PWMduty = 100%)
(RISET = 30.1 kΩ)
19
R1214Z
NO.EA-327-170919
5) Load Transient Response
VIN = 3.6 V/ 8s2p LEDs
VIN = 3.6 V/ 8s2p LEDs
R1214Z221A (fPWM= 20kHz, PWMduty= 10%→90%) R1214Z221A (fPWM= 20kHz, PWMduty= 90%→10%)
(RISET = 30.1 kΩ/ CISET = 0 µF)
(RISET = 30.1 kΩ/ CISET = 0 µF)
VIN = 3.6 V/ 8s2p LEDs
VIN = 3.6 V/ 8s2p LEDs
R1214Z221A (fPWM= 20kHz, PWMduty= 10%→90%) R1214Z221A (fPWM= 20kHz, PWMduty= 90%→10%)
(RISET = 30.1 kΩ/ CISET = 2.0 µF)
(RISET = 30.1 kΩ/ CISET = 2.0 µF)
20
R1214Z
NO.EA-327-170919
6) Electrical Characteristics
6-1) UVLO Voltage vs. Ambient Temperature
6-2) LED Regulated Voltage vs. Ambient Temperature
R1214ZxxxA/B
R1214ZxxxC/D
6-3) LED Current vs. Ambient Temperature
R1214ZxxxA/B
R1214ZxxxC/D
21
R1214Z
NO.EA-327-170919
6-4) Nch ON Resistance vs. Ambient Temperature
6-5) Oscillator Frequency vs. Ambient Temperature
R1214Z211x
R1214Z221x
6-6) Maxduty vs. Ambient Temperature
R1214Z211x
22
R1214Z221x
R1214Z
NO.EA-327-170919
6-7) LxOVP Detect Voltage
vs. Ambient Temperature
6-8) LEDOVP Detect Voltage
vs. Ambient Temperature
6-9) Soft start Time vs. Ambient Temperature
6-10) Lx Limit Current vs. Ambient Temperature
23
POWER DISSIPATION
WLCSP-9-P1
Ver. A
The power dissipation of the package is dependent on PCB material, layout, and environmental conditions.
The following conditions are used in this measurement.
Measurement Conditions
High Wattage Land Pattern
Environment
Mounting on Board (Wind Velocity = 0 m/s)
Board Material
Glass Cloth Epoxy Plastic (Four-layers)
Board Dimensions
76.2 mm × 114.3 mm × 1.6 mm
Copper Ratio
Outer Layers (First and Fourth Layers): Approx. 60%
Inner Layers (Second and Third Layers): 100%
Measurement Result
(Ta = 25°C, Tjmax = 125°C)
High Wattage Land Pattern
Power Dissipation
1190 mW
Thermal Resistance
θja = (125 − 25°C) / 1.19 W = 84°C/W
76.2
1200
50
1000
50
High Wattage Land Pattern
800
114.3
Power Dissipation PD (mW)
40
1400
600
400
200
0
0
20
40
60
80
100
120
140
High Wattage
Ambient Temperature (℃)
IC Mount Area (mm)
Power Dissipation vs. Ambient Temperature
Measurement Board Pattern
i
PACKAGE DIMENSIONS
WLCSP-9-P1
Ver. A
WLCSP-9-P1 Package Dimensions (Unit: mm)
i
Visual Inspection Criteria
WLCSP
VI-160823
No.
1
Inspection Items
Package chipping
2
Si surface chipping
3
No bump
Marking miss
4
Inspection Criteria
Figure
A≥0.2mm is rejected
B≥0.2mm is rejected
C≥0.2mm is rejected
And, Package chipping to Si surface
and to bump is rejected.
A≥0.2mm is rejected
B≥0.2mm is rejected
C≥0.2mm is rejected
But, even if A≥0.2mm, B≤0.1mm is
acceptable.
No bump is rejected.
To reject incorrect marking, such as
another product name marking or
5
6
7
No marking
Reverse direction of
marking
Defective marking
8
Scratch
9
Stain and Foreign
material
another lot No. marking.
To reject no marking on the package.
To reject reverse direction of marking
character.
To reject unreadable marking.
(Microscope: X15/ White LED/ Viewed
from vertical direction)
To reject unreadable marking
character by scratch.
(Microscope: X15/ White LED/ Viewed
from vertical direction)
To reject unreadable marking
character by stain and foreign material.
(Microscope: X15/ White LED/ Viewed
from vertical direction)
i
1. The products and the product specifications described in this document are subject to change or discontinuation of
production without notice for reasons such as improvement. Therefore, before deciding to use the products, please
refer to Ricoh sales representatives for the latest information thereon.
2. The materials in this document may not be copied or otherwise reproduced in whole or in part without prior written
consent of Ricoh.
3. Please be sure to take any necessary formalities under relevant laws or regulations before exporting or otherwise
taking out of your country the products or the technical information described herein.
4. The technical information described in this document shows typical characteristics of and example application circuits
for the products. The release of such information is not to be construed as a warranty of or a grant of license under
Ricoh's or any third party's intellectual property rights or any other rights.
5. The products listed in this document are intended and designed for use as general electronic components in standard
applications (office equipment, telecommunication equipment, measuring instruments, consumer electronic products,
amusement equipment etc.). Those customers intending to use a product in an application requiring extreme quality
and reliability, for example, in a highly specific application where the failure or misoperation of the product could result
in human injury or death (aircraft, spacevehicle, nuclear reactor control system, traffic control system, automotive and
transportation equipment, combustion equipment, safety devices, life support system etc.) should first contact us.
6. We are making our continuous effort to improve the quality and reliability of our products, but semiconductor products
are likely to fail with certain probability. In order to prevent any injury to persons or damages to property resulting from
such failure, customers should be careful enough to incorporate safety measures in their design, such as redundancy
feature, fire containment feature and fail-safe feature. We do not assume any liability or responsibility for any loss or
damage arising from misuse or inappropriate use of the products.
7. Anti-radiation design is not implemented in the products described in this document.
8. The X-ray exposure can influence functions and characteristics of the products. Confirm the product functions and
characteristics in the evaluation stage.
9. WLCSP products should be used in light shielded environments. The light exposure can influence functions and
characteristics of the products under operation or storage.
10. There can be variation in the marking when different AOI (Automated Optical Inspection) equipment is used. In the
case of recognizing the marking characteristic with AOI, please contact Ricoh sales or our distributor before attempting
to use AOI.
11. Please contact Ricoh sales representatives should you have any questions or comments concerning the products or
the technical information.
Halogen Free
Ricoh is committed to reducing the environmental loading materials in electrical devices
with a view to contributing to the protection of human health and the environment.
Ricoh has been providing RoHS compliant products since April 1, 2006 and Halogen-free products since
April 1, 2012.
https://www.e-devices.ricoh.co.jp/en/
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