R5210D26A-TR [RICOH]
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6;
| 型号： | R5210D26A-TR |
| 厂家： | 
RICOH ELECTRONICS DEVICES DIVISION |
| 描述： | Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6 光电二极管 |
| 文件： | 总13页 (文件大小：136K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
2002.9.12
12345
Step-down DC/DC Converter with VR and Reset
R5210X Series
n
OUTLINE
The R5210X is CMOS-based PWM step-down DC/DC converter combined with a voltage regulator
(VR) and a voltage detector (VD), with low supply current.
Each of these ICs consists of an oscillator, a PWM control circuit, a reference voltage unit, an error
amplifier, a soft-start circuit, a current limit circuit, a phase compensation circuit, a resistor net for
voltage detect circuit, an output driver transistor, and so on. A low ripple, high efficiency step-down
DC/DC converter can be easily composed of this IC with some external components, or an inductor, a
diode, and capacitors.
The oscillator frequency is 800kHz, therefore small inductor and capacitor can be used with this IC.
Further, this IC equips the under voltage lockout function (UVLO). If the input voltage becomes 2.35V
(Typ.) or less, the output of DC/DC converter is turned off. However, embedded voltage regulator and
the detector continue to operate.
The voltage regulator consists of a reference voltage unit, a resistor net for voltage detect circuit,
an error amplifier, an output driver transistor, and so on.
The built-in voltage detector supervises the input voltage and the output is N-channel open drain type.
Power-on reset delay time is also included and internally set typically at 10ms.
n
FEATURES
l
l
l
l
l
l
l
l
l
Wide Range of Input Voltage · · · · · · · · · · · · ·2.7V~5.5V
Built-in Soft-start Function (Typ. 2ms) and built-in power-on reset delay (Typ. 10ms)
Maximum Output Current · · · · · ·500mA(DC/DC), 200mA(VR)
High Accuracy Output Voltage · · · · · · · · · ·±2.0%(DC/DC and Voltage Regulator Output)
Accuracy of voltage detector · · · · · · · · · · · · · · · · · ·±2.5%
Output Voltage(VR) · · · · · · · · ·Stepwise Setting with a step of 0.1V in the range of 2.5V to 3.6V
Output Voltage(DC/DC) · · · · · · Stepwise Setting with a step of 0.1V in the range of 1.5V to 3.3V
Output Voltage(VD) · · · · · · · · ·Stepwise Setting with a step of 0.1V in the range of 3.0V to 4.5V
Packages · · · · · SOT23-6W(thickness: Max. 1.3mm) or HSON6(thickness: Max. 0.9mm)
n
APPLICATIONS
l Power source for hand-held communication equipment, CD or DVD drives.
l Power source for battery-powered equipment.
12345
Rev. 1.11
- 1 -
n
BLOCK DIAGRAM
Current Limit
CONTROL
VIN
OSC
VOUT1
OUTPUT
CONTROL
Vref
Lx
Soft Start
U.V.L.O.
Current Limit
Vref
Delay Circuit
Vref
VOUT2
OUT
VD
GND
n
SELECTION GUIDE
In the R5210X Series, the output voltage combination for the ICs can be selected at the user’s request.
The selection can be made with designating the part number as shown below ;
R5210XXXXX-TR <- Part Number
•
•
•
•
a
b
c
d
Code
Contents
a
Designating the Package type:
N: SOT23-6W
D: HSON6(Under Development)
b
c
Output Voltage Combination Code Number
Designation of Optional Function
A (Standard)
d
Designation of Taping Type: Refer to Taping specification.
12345
Rev. 1.11
- 2 -
n
PIN CONFIGURATIONS
l SOT-23-6W
6
1
5
4
3
(Mark side)
2
R5210NXXXX
l
HSON6
6
5
4
(Mark side)
R5210DXXXX
n PIN DESCRIPTION
Symbol
Description
Pin No.
R5210N R5210D
1
2
3
4
5
6
5
4
3
1
2
6
VOUT2 Output Pin of Voltage Regulator
VDOUT Output Pin of Voltage Detector (N-channel open-drain output type)
VOUT1 DC/DC converter Step-down Output monitoring Pin
Lx
Switching Pin (P-channel open-drain output type)
GND Ground Pin
VOUT Voltage Supply Pin
12345
Rev. 1.11
- 3 -
n
ABSOLUTE MAXIMUM RATINGS
(GND=0V)
Symbol
Item
Rating
6.5
Unit
V
VIN
VLX
VIN Pin Voltage
Lx Pin Voltage
-0.3~VIN+0.3
-0.3~VIN+0.3
-0.3~VIN+0.3
-0.3~VIN+0.3
700
V
VOUT1
VOUT2
VDOUT
ILX
VOUT1 Pin Voltage
V
VOUT2 Pin Voltage
V
VDOUT Pin Voltage
V
Lx Pin Output Current
mA
mA
mW
mW
IOUT2
PD
VOUT2 Pin Output Current
Power Dissipation(SOT23-6W)
Power Dissipation
250
250
PD
400
(HSON-6/Under Development)
Operating Temperature Range
Storage Temperature Range
Topt
Tstg
-40~+85
°C
°C
-55~+125
n
ELECTRICAL CHARACTERISTICS
lR5210N001A
(Topt=25°C)
Symbol
Item
Conditions
Min.
2.7
Typ. Max. Unit
VIN
IDD
Operating Input Voltage
Supply Current
5.5
V
VIN=5.0V, VOUT1=5.0V
150
300 mA
VUVLO1 UVLO Detector Threshold Voltage
2.15 VUVLO
2
V
-0.15
VUVLO2 UVLO Release Voltage
DC/DC Part
2.35
2.50
2.65
V
Symbol
Item
Conditions
VIN=5.0V, at no load
-40°C £ Topt £ 85°C
Min.
Typ. Max. Unit
VOUT1 DC/DC Output Voltage
2.646 2.700 2.754
V
DVOUT1/ DC/DC Output Voltage
±100
ppm
/°C
DT
Temperature Coefficient
Oscillator Frequency
fOSC
VIN=5.0V
640
800
1.5
960 kHz
kHz/
DfOSC/ Oscillator Frequency Temperature -40°C £ Topt £ 85°C
DT
RLX
Coefficient
°C
Lx on Resistance
Lx Leakage Current
Lx Current Limit
VIN=5.0V, ILX=100mA
VIN=VOUT1=5.0V, VLX=0V
VIN=5.0V
0.4
0.01
650
0.8
W
ILXleak
ILxlim
5.00 mA
500
100
0.7
mA
%
Maxdty Maximum duty cycle
Tstart
Soft-start Time
VIN=5.0V
2.0
5.0
ms
VR part
Symbol
Item
Conditions
VIN=5.0V, IOUT2=10mA
VIN=5.0V
Min.
Typ. Max. Unit
VOUT2 VR Output Voltage
3.332 3.400 3.468
200
V
mA
mV
V
IOUT2
Maximum Output Current of VR
VREG2 VR Load Regulation
VDIF2 Dropout Voltage
VIN=5.0V, 1mA £IOUT2£80mA
IOUT2=100mA
30
0.2
70
0.3
ILIM2
Short Current Limit
VOUT2=0V
50
mA
ppm
/°C
DVOUT2/ VR Output Voltage
-40°C £ Topt £ 85°C
±100
DT
Temperature Coefficient
12345
Rev. 1.11
- 4 -
VD part
Symbol
Item
Conditions
Min.
Typ. Max. Unit
-VDET VD Detector Threshold
4.095 4.200 4.305
V
ppm
/°C
V
D-VDET/ VD Detector Threshold
-40°C £ Topt £ 85°C
±100
DT
Temperature Coefficient
Hysteresis Range
VHYS
-VDET
´ 0.05
tpLH
VD Output Delay Time for Release
5
2
10
7
20
15
ms
IDOUTL VDOUT ”L” Output Current
VIN=2.0V, VDOUT=0.1V
mA
n
l
TYPICAL APPLICATION AND APPLICATION HINTS
R5210NXXXA
C3
R1
VOUT2
V
V
IN
OUT2
C1
VDOUT
DOUT
GND
C2
V O U T 1
OUT1
V
L1
D
1
Examples of Components
Inductor L1: LQH4C (Murata, 10mH) or LDR655312T (TDK)
Shottky Diode D1: RB491D (Rohm) or EP05Q03L (Nihon Inter), Pull-up Resistor R1: 50kW
Capacitors: C1=10mF (Ceramic Capacitor) C2: 22mF (Tantalum Capacitor) C3: 10mF (Tantalum
Capacitor)
When you use these ICs, consider the following issues;
l Set external components as close as possible to the IC and minimize the connection between the
componentsꢀ and the IC. In particular, a capacitor should be connected to between VIN and GND with the
minimum connection. Make sufficient grounding, and reinforce supplying. A large switching current flows
through the connection of powerꢀsupply, an inductor and the connection of VOUT1. If the impedance of the
connection of power supply or ground is high, theꢀvoltage level of power supply of the IC fluctuates with the
switching current. This may cause unstable operation ofꢀthe IC.
l Use a capacitor with a capacity of 10mF or more for VIN and GND, and with low ESR ceramic type. In terms
of VOUT1, use a capacitor with a capacity of 22mF or more, and with good high frequency characteristics
such as tantalum capacitors.
l Choose an inductor that has sufficiently small D.C. resistance and large allowable current and which is
12345
Rev. 1.11
- 5 -
hard to reach magnetic saturation. If the value of inductance of an inductor is extremely small, the ILX, which
flows through Lx transistor and an inductor, may exceed the absolute maximum rating at the maximum loading.
Use an inductor with appropriate inductance.
l Use a diode of a Schottky type with high switching speed, and also pay attention to its current capacity.
l If the spike noise of Lx pin is too large, make snub circuit (such as serial connection of CR) between Lx and
GND, then the noise will be reduced. The time constant of the CR depends on the actual PCB, so evaluate it
on the actual PCB.
l
If the load current of the voltage regulator is small, because of the switching noise of DC/DC converter,
the output voltage of VOUT2 may be large. To avoid this, use the voltage regulator with a load current at
least 1mA.
P The performance of power source circuits using these ICs extremely depends upon the peripheral circuits.
Pay attention in the selection of the peripheral circuits. In particular, design the peripheral circuits in a way
that the values such as voltage, current, and power of each component, PCB patterns and the IC do not
exceed their respected rated values.
n OPERATION of step-down DC/DC converter and Output Current
The step-down DC/DC converter charges energy in the inductor when Lx transistor is ON, and discharges
the energy from the inductor when Lx transistor is OFF and controls with less energy loss, so that a lower
output voltage than the input voltage is obtained. The operation will be explained with reference to the
following diagrams:
<Basic Circuits>
<Current through L>
i1
ILmax
IOUT
L
ILmin
topen
VI
Lx Tr
SD
VOU
i2
CL
ton
toff
T=1/fosc
Step 1: Lx Tr. turns on and current IL (=i1) flows, and energy is charged into CL. At this moment, IL increases
from ILmin (=0) to reach ILmax in proportion to the on-time period (ton) of LX Tr.
Step 2: When Lx Tr. turns off, Schottky diode (SD) turns on in order that L maintains IL at ILmax, and current
IL (=i2) flows.
Step 3: IL decreases gradually and reachesILmin after a time period oftopen, and SD turns off, provided that
in the continuous mode, next cycle starts before IL becomes to 0 becausetoff time is not enough. In this case,
IL value is from this ILmin (>0).
In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton),
with the oscillator frequency (fosc) being maintained constant.
l Discontinuous Conduction Mode and Continuous Conduction Mode
The maximum value (ILmax) and the minimum value (ILmin) current which flow through the inductor is the
12345
Rev. 1.11
- 6 -
same as those when Lx Tr. turns on and when it turns off.
The difference between ILmax and ILmin, which is represented by DI;
DI = ILmax – ILmin = VOUT ´ topen / L = (VIN-VOUT)´ ton/L×××Equation 1
Where, T=1/fosc=ton+toff
duty (%)=ton/T´ 100=ton´ fosc ´ 100
topen
£ toff
In Equation 1, VOUT´ topen/L and (VIN-VOUT)´ ton/L are respectively shown the change of the current at
ON, and the change of the current at OFF.
When the output current (IOUT) is relatively small,topen <toff as illustrated in the above diagram. In this case,
the energy is charged in the inductor during the time period of ton and is discharged in its entirely during the
time period of toff, therefore ILmin becomes to zero (ILmin=0). When Iout is gradually increased, eventually,
topen becomes to toff (topen=toff), and when IOUT is further increased, ILmin becomes larger than zero
(ILmin>0). The former mode is referred to as the discontinuous mode and the latter mode is referred to as
continuous mode.
In the continuous mode, when Equation 1 is solved for ton and assumed that the solution is tonc,
tonc=T´ VOUT/VIN××× Equation 2
When ton<tonc, the mode is the discontinuous mode, and whenton=tonc, the mode is the continuous mode.
n OUTPUT CURRENT AND SELECTION OF EXTERNAL COMPONENTS
When Lx Tr. is “ON”:
(Wherein, Ripple Current P-P value is described as IRP, ON resistance of LX Tr. is described asRp the direct
current of the inductor is described as RL.)
VIN=VOUT+(Rp+RL)´ IOUT+L´ IRP/ton ×××Equation 3
When Lx Tr. is “OFF”:
L´ IRP/toff = VF+VOUT+RL´ IOUT ×××Equation 4
Put Equation 4 to Equation 3 and solve for ON duty, ton/(toff+ton)=DON,
DON=(VOUT+VF+RL´ IOUT)/(VIN+VF-Rp´ IOUT)×××Equation 5
Ripple Current is as follows;
IRP=(VIN-VOUT-Rp´ IOUT-RL´ IOUT)´ DON/f/L ¼ Equation 6
Wherein, peak current that flows through L, Lx Tr., and SD is as follows;
ILmax=IOUT+IRP/2¼ Equation 7
Consider ILmax, condition of input and output and select external components.
HThe above explanation is directed to the calculation in an ideal case in continuous mode.
12345
Rev. 1.11
- 7 -
n Timing Chart
(-
Vdet+Vhys)
-
Vdet
V UVLO2
VUVLO1
IN Voltage
V
Soft-start Time
VOUT1
Voltage
Lx Voltage
Delay for Release
VD
VDDelay for Release
Voltage
DOUT
V
V
OUT2Voltage
The timing chart which is shown in the previous page describes the relation of supply voltage changes with
time and each output of DC/DC converter, voltage detector, and voltage regulator.
(1) DC/DC converter
When the power turns on and in the case of rising the V IN voltage, while the V IN voltage is at UVLO release
level (VUVLO2) or less, the operation of the DC/DC converter stops and does not make switching, therefore
VOUT1 voltage does not rise.
When the VIN voltage becomes UVLO release level or more, the DC/DC converter starts soft-start
operation, and start switching, then VOUT1 will rise. After the soft-start time, if VIN voltage becomes set
VOUT1 level or more, VOUT1 will be settled at VOUT1 set output voltage. If VIN voltage becomes UVLO
detector threshold level (VUVLO1) or less, the DC/DC converter stops switching then Lx transistor in the IC
turns off.
(2) Voltage Detector
If the VIN voltage is at VD detector threshold level or less, the N-channel transistor of V DOUT pin turns on
and outputs “L” to VDOUT pin. Then, when the VIN voltage becomes VD detector threshold level + its
hysteresis range (-VDET+VHYS) or more, after VD delay for release (tpLH) passing, the N-channel
transistor inside the IC turns off, VDOUT pin voltage reaches to the pull-up voltage. Besides, the release
circuit for VD starts after soft-start time and under this condition, VIN voltage should be (-VDET+VHYS) or
more.
(3) Voltage Regulator
The voltage regulator always operates even if UVLO function would work. Therefore, VOUT2 voltage is
12345
Rev. 1.11
- 8 -
nearly equal to VIN voltage. Actual value depends on the load current. When the V IN voltage becomes set
VOUT2 voltage or more, VOUT2 voltage will be the set output voltage.
n TEST CIRCUITS
A) Supply Current
B) UVLO Detector Threshold/ Released Voltage
O SCILLOSCO PE
V
IN
A
V
Lx
IN
V
O U T 1
V
OUT1
GND
GND
C) Lx Leakage Current
D) Lx On Resistance
V
Lx
IN
V
IN
Lx
O U T 1
A
V
V
O U T 1
V
GND
GND
E) Lx Current Limit
F) VOUT1 Output Voltage
O S CILLOSCO PE
O SC ILLOSCO PE
V
Lx
IN
V
Lx
V
O U T 1
V
O U T 1
VOUT2
GND
GND
12345
Rev. 1.11
- 9 -
G) Oscillator Frequency, Soft-start Time
O S C I L L O S C O P E
O S C I L L O S C O P E
V
V
IN
V
O U T 1
H) VOUT2 Output Voltage, Load Regulation, Dropout
Voltage, Current Limit, Short Current Limit
I) VDOUT Detector Threshold, Hysteresis Range, VD
Output Delay Time for Release
V
Lx
IN
V
Lx
V
OUT1
V
O U T 1
VOUT2
V
GND
GND
DOUT
I
OUT2
O SC ILLOSCOPE
J) VDOUT “L” Output Current
V
IN
V
OUT1
GND
D O U T
V
A
Typical Characteristics were obtained with using the test circuits as follows;
Typical Application Circuit: Typical Characteristics 1) 2) 11) 12)
Test Circuit F: Typical Characteristics 3)
Test Circuit G: Typical Characteristics 6) 7)
Test Circuit H: Typical Characteristics 4) 9) 10)
Test Circuit I: Typical Characteristics 5) 8)
12345
Rev. 1.11
- 10 -
n TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current
2) Efficiency vs. Output Current
L1=22uH,C1=10uF
L1=22uH,C1=10uF
R5210N001A
R5210N001A VOUT1=2.7V,IOUT2=0mA
VOUT1=2.7V,IOUT2=0mA
2.8
2.75
2.7
100
90
80
70
60
50
40
30
20
10
0
VIN=4.5V
VIN=5.0V
VIN=5.5V
Vin=4.5V
Vin=5.0V
Vin=5.5V
2.65
2.6
0
100
200
300
400
500
0
100
200
300
400
500
Output Current IOUT1 [mA]
OUT1
Output Current I
[mA]
3) DC/DC Output Voltage vs. Temperature
4) VR Output Voltage vs. Temperature
R5210N001A
2.80
R5210N001A
3.50
2.75
2.70
2.65
2.60
3.45
3.40
3.35
3.30
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
5) Detector Threshold vs. Temperature
6) Oscillator Frequency vs. Temperature
R5210N001A
4.4
R5210N001A
1000
900
800
700
600
4.3
4.2
4.1
4.0
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
12345
Rev. 1.11
- 11 -
8) Output Delay Time for Release VD vs. Temperature
7) Soft-start time vs. Temperature
R5210N001A
4.0
R5210N001A
20
16
12
8
3.0
2.0
1.0
0.0
4
0
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
9) VR Output Voltage vs. Output Current
10) VR Output Voltage vs. Output Current (zoomed)
R5210N001A
4
R5210N001A
3.43
3.5
3
3.42
3.41
3.4
2.5
2
3.39
3.38
3.37
3.36
1.5
1
0.5
0
0
50
100
150
200
0
50
100
150
200
250
300
Output Current IOUT2 [mA]
Output Current IOUT2 [mA]
11) Load Transient Response 1
12) Load Transient Response 1
12345
Rev. 1.11
- 12 -
12345
Rev. 1.11
- 13 -
相关型号：
R5210D26A-TR-FA
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D27A-TR
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D27A-TR-FA
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D28A-TR-FA
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D29A-TR-FA
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D30A-TR
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
R5210D30A-TR-FA
Switching Regulator, Current-mode, 0.7A, 960kHz Switching Freq-Max, CMOS, PDSO6, 0.90 MM HEIGHT, HSON-6
RICOH
©2020 ICPDF网 联系我们和版权申明