ROHM BD9533EKN

TECHNICAL NOTE
High-performance Regulator IC Series for PCs
Switching Regulators
for DDR-SDRAM Cores
BD9533EKN
●Description
BD9533EKN is a switching regulator controller with high output current which can achieve low output voltage (0.7V to 2.0V)
from a wide input voltage range (4.5V to 28V). High efficiency for the switching regulator can be realized by utilizing an
3
TM
external N-MOSFET power transistor. A new technology called H Reg is a Rohm proprietary control method to realize
ultra high transient response against load change. SLLM (Simple Light Load Mode) technology is also integrated to improve
efficiency in light load mode, providing high efficiency over a wide load range. For protection and ease of use, the soft start
function, variable frequency function, short circuit protection function with timer latch, over voltage protection function and
REF synchronous function are all built in. This switching regulator is specially designed for the DDR-SDRAM core.
●Features
3
TM
1) H Reg Switching Regulator Controller
2) Light Load Mode and Continuous Mode Changeable
3) Thermal Shut Down (TSD), Under Voltage LockOut (UVLO), Over Current Protection (OCP),
Over Voltage Protection (OVP), Short Circuit Protection (SCP) built-in
4) Soft start function to minimize rush current during startup
5) Switching Frequency Variable (f=200KHz～600KHz)
6) HQFN20V Package
●Applications
Laptop PC, Desktop PC, LCD-TV, Digital Components
Sep. 2008
●Maximum Absolute Ratings (Ta=25℃)
Parameter
Input Voltage 1
Input Voltage 2
Input Voltage 3
BOOT Voltage
BOOT-SW Voltage
HG-SW Voltage
LG Voltage
REF Voltage
Output Voltage
ILIM/SCP/SS/FS/SLLM Voltage
VREG Voltage
EN Input Voltage
Power Dissipation 1
Power Dissipation 2
Power Dissipation 3
Power Dissipation 4
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Symbol
VCC
VDD
VIN
BOOT
BOOT-SW
HG-SW
LG
REF
VOUT/Is+/IsILIM/SCP/SS/FS/SLLM
VREG
EN
Pd1
Pd2
Pd3
Pd4
Topr
Tstg
Tjmax
Limit
7 *1
7 *1
30 *1
35 *1
7 *1
7 *1
VDD
VCC
VCC
VCC
VCC
7 *1
0.5 *2
0.75 *3
1.75 *4
2.00 *5
-10～+100
-55～+150
+150
Unit
V
V
V
V
V
V
V
V
V
V
V
V
W
W
W
W
℃
℃
℃
*1 Not to exceed Pd.
*2 Reduced by 4mW for each increase in Ta of 1℃ over 25℃ (when don’t mounted on a heat radiation board )
*3 Reduced by 6mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB.)
*4 Reduced by 14mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB.)
*5 Reduced by 16mW for increase in Ta of 1℃ over 25℃. (when mounted on a board 70.0mm×70mm×1.6mm Glass-epoxy PCB.)
●Operating Conditions (Ta=25℃)
Parameter
Input Voltage 1
Input Voltage 2
Input Voltage 3
BOOT Voltage
SW Voltage
BOOT-SW Voltage
SLLM Input Voltage
EN Input Voltage
Output setting voltage
Is Input Voltage
MIN ON Time
Symbol
VCC
VDD
VIN
BOOT
SW
BOOT-SW
SLLM
EN
REF
Is+/IsTonmin
★ This product should not be used in a radioactive environment.
2/20
MIN
4.5
4.5
4.5
4.5
-0.7
4.5
0
0
0.7
0.7
-
MAX
5.5
5.5
28
33
28
5.5
5.5
5.5
2.0
2.7
200
Unit
V
V
V
V
V
V
V
V
V
V
nsec
●ELECTRICAL CHARACTERISTICS
(unless otherwise noted, Ta=25℃ VCC=5V,VDD=5V,EN/SLLM=5V,VIN=12V,REF=1.8V,RFS=68kΩ)
Standard Value
Parameter
Symbol
Unit
Condition
MIN
TYP
MAX
[Whole Device]
VCC Bias Current
Icc
700
900
μA
VIN Bias Current
Iin
100
200
μA
VCC Standby Current
Iccstb
0
10
μA EN=0V
VIN Standby Current
Iinstb
100
200
μA EN=0V
EN Low Voltage
Enlow
GND
0.8
V
EN HighVoltage
Enhigh
2.3
5.5
V
EN Bias Current
Ien
7
10
μA
Ireg=100μA
VREG Voltage
Vreg
2.475
2.500
2.525
V
Ta=-10℃ to 100℃*
[Under Voltage Locked Out ]
VCC threshold voltage
Vcc_UVLO
4.1
4.3
4.5
V
VCC:Sweep up
VCC hysteresis voltage
dVcc_UVLO
100
160
220
mV VCC:Sweep down
VIN threshold voltage
Vin_UVLO
4.1
4.3
4.5
V
VIN:Sweep up
VIN hysteresis voltage
dVin_UVLO
100
160
220
mV VIN:Sweep down
VREG threshold voltage
Vreg_UVLO
2.0
2.2
2.4
V
VREG:Sweep up
VREG hysteresis voltage
dVreg_UVLO
100
160
220
mV VREG:Sweep down
[H3RegTM]
Frequency
Fosc
300
kHz
ON Time
Ton
400
500
600
nsec
MAX ON Time
Tonmax
3
μsec
MIN OFF Time
Toffmin
450
550
nsec
[FET Driver]
HG Higher side ON resistor
HGhon
3.0
6.0
Ω
HG Lower side ON resistor
HGlon
2.0
4.0
Ω
LG Higher side ON resistor
LGhon
2.0
4.0
Ω
LG Lower side ON resistor
LGlon
0.5
1.0
Ω
[Dead Time]
HG rising
HGdead
50
nsec
LG rising
LGdead
50
nsec
[SCP]
REF×0.65
REF×0.7
REF×0.75
SCP Detect Voltage
Vscp
V
SCP threshold voltage
Vscpth
1.2
1.25
1.3
V
Charge current
Iscp
1.5
2
2.5
μA
Standby voltage
Vscp_stb
50
mV
[OVP]
REF×1.16
REF×1.2
REF×1.24
OVP Detect Voltage
VOVP
V
[Soft start]
Charge current
Iss
1.5
2
2.5
μA
Standby voltage
Vss_stb
50
mV
[Over Current Protection Block]
ILIM=0.5V
Current limit threshold1
Ilim1
43
50
57
mV
Ta=-10℃ to 100℃*
Current limit threshold2
Ilim2
160
200
240
mV ILIM=2.0V
Reverse current limit threshold1
ReIlim1
-50
mV ILIM=0.5V
Reverse current limit threshold2
ReIlim2
-200
mV ILIM=2.0V
[VOUT setting ]
VOUT offset voltage1
Voutoff1
REF-7m
REF
REF+7m
V
Ta=-10℃ to 100℃*
VOUT bias current
Ivout
-100
0
100
nA
REF bias current
Iref
-100
0
100
nA
Is+ Input current
IIs+
-1
0
1
μA Is+=1.8V
Is- Input current
IIs-1
0
1
μA Is-=1.8V
[SLLM ]
Continuous mode threshold
Vthcon
VCC-0.5
VCC
V
SLLM threshold
VthSLLM
GND
0.5
V
* Design Guarantee
3/20
600
2.500
590
2.498
580
2.496
4.30
4.25
VCC[V]
570
2.494
550
-10
30
50
Ta(℃)
70
4.00
-10
90
10
Fig.1 Ta vs Icc
70
-10
90
4.10
1.6
EN[V]
2.05
10
30
50
Ta(℃)
70
-10
90
Fig.4 Ta vs UVLO (VIN)
10
30
50
Ta(℃)
Sweep down
70
1.2
-10
90
Fig.5 Ta vs UVLO (VREG)
2.8
90
1.5
1.3
Sweep down
1.90
4.00
70
1.4
1.95
4.05
50
Ta( ℃)
Sweep up
Sweep up
2.00
Sweep down
-10
30
1.7
2.10
4.15
10
Fig.3 Ta vs UVLO (VCC)
2.15
Sweep up
VREG[V]
10
30
50
Ta( ℃)
70
90
Fig.6 Ta vs EN Threshold
1000
600
900
2.4
500
800
2.0
TON [nsec]
700
1.6
1.2
Right: -10℃
Middle: 25℃
Left: 100℃
0.8
0.4
600
TON [nsec]
VIN[V]
50
Ta(℃)
2.20
4.20
VREG(V)
30
Fig.2 Ta vs VREG
4.30
4.25
Sweep down
4.05
2.490
10
4.15
4.10
2.492
560
Top: -10℃
Middle: 25℃
Bottom: 100℃
500
400
300
200
400
300
Top: -10℃
Middle: 25℃
Bottom: 100℃
200
100
100
0.0
0
0
0
1.5
3
4.5
Vcc(V)
6
0.6
0.8
1
1.2
1.4
1.6
1.8
0.6
2
1000
VOUT-REF [mV]
TON [nsec]
Top: -10℃
Middle: 25℃
Bottom: 100℃
Top: -10℃
Middle: 25℃
Bottom: 100℃
600
400
100
200
50
0
1
1.2
1.4
1.6
REF [V]
Fig.10 REF-ON TIME
(VIN=25V)
1.8
2
1.8
1
0
-1
-2
0
0.8
1.6
2
800
250
1.4
3
300
0.6
1.2
Fig.9 REF vs ON TIME
(VIN=12V)
1200
350
150
1
REF [V]
Fig.8 REF vs ON TIME
(VIN=7V)
400
200
0.8
REF [V]
Fig.7 VCC vs VREG (Start up)
TON [nsec]
Sweep up
4.20
VREG[V]
Icc(uA)
●Reference Data
-3
5
10
15
20
VIN [V]
Fig.11 VIN-ON TIME
(REF=1.8V)
4/20
25
-10
10
30
50
70
Ta [℃]
Fig.12 Ta vs VOUT offset
90
2
●Reference Data
frequency[kHz]
50
48
400
330
360
310
290
270
ILIM=0.5V
-10
10
30
50
Te [℃]
70
10
30
50
Ta(℃)
70
90
0
Fig.14 Ta vs Frequency
Fig.13 Ta vs current limit
threshould
100
SLLM
80
40
Continuous
mode
40
20
1
10
100
Io(mA)
1000
Fig.16 Io vs Efficiency
(VIN=7V)
VOUT
HG/LG
IOUT
Fig.19 Load Transient
Response (VIN=7V)
VOUT
10000
Continuous
mode
20
0
0
1
10
100
Io(mA)
1000
10000
Fig.17 Io vs Efficiency
(VIN=12V)
1
10
1000
Fig.18 Io vs Efficiency
(VIN=20V)
VOUT
VOUT
HG/LG
HG/LG
IOUT
IOUT
Fig.20 Load Transient Response
(VIN=12V)
100
Io(mA)
Fig.21 Load Transient
Response (VIN=19V)
VOUT
VOUT
HG/LG
HG/LG
HG/LG
IOUT
Fig.22 Load Transient
Response (VIN=7V)
25
SLLM
40
20
0
20
60
η[%]
η[%]
80
60
Continuous
mode
10
15
VIN(V)
100
SLLM
60
5
Fig.15 VIN vs Frequency
100
80
Io=0A
280
200
-10
90
320
240
250
46
Io=2A
η[%]
⊿Is [mV]
52
350
frequency[kHz]
54
IOUT
IOUT
Fig.23 Load Transient Response
(VIN=12V)
5/20
Fig.24 Load Transient
Response (VIN=19V)
10000
●Reference Data
VOUT
IL
VOUT
VOUT
IL
IL
HG/LG
HG/LG
HG/LG
Fig.25 SLLM
(IOUT=0A)
Fig.27 SLLM
(IOUT=1A)
Fig.26 SLLM
(IOUT=0.4A)
IL
IL
IL
HG/LG/SW
HG/LG/SW
HG/LG/SW
Fig.28 Continuous MODE
(Io=0A)
Fig.29 Continuous MODE
(Io=4A)
Fig.30 Continuous MODE
(Io=5A)
VIN
VIN
EN
HG/LG
HG/LG
SS
VOUT
VOUT
VOUT
Fig.31 VIN change
(5→19V)
Fig.32 VIN change
(19→5V)
1.82
700
400
Continuous
mode
350
Continuous
mode
Frequency [kHz]
300
1.8
SLLM
1.79
600
Frequency [kHz]
1.81
VOUT [V]
Fig.33 FS VIN wake up
250
200
150
SLLM
100
0
1
10
100
Iout [mA]
1000
Fig.34 IOUT-VOUT
10000
400
300
200
50
1.78
500
From upper side VIN=5V
7V
12V
16V
19V
100
1
10
100
1000
10000
Iout [mA]
Fig.35 IOUT-Frequency
6/20
30 40 50 60 70 80 90 100 110 120 130
RFS [kΩ]
Fig.36 FS resistance- Frequency
●Block Diagram
VCC
2
EN
4
Reference
Block
5
VIN
19
VREG
16
SS
VDD
UVLO
VREG
VIN
SS
2.5V
2.5VReg
Soft Start Block
SCP
7
REF×1.2
SCP
REF×0.7
SS×0.7
VOUT
OVP
H Reg
REF
TM
Q
R
Driver
SLLM
Circuit
Controller
20
Block
VOUT
TSD
Thermal
Protection
1
S
ILIM
SW
VDD
12
11
LG
10
-
+
UVLO
ILIM
SCP
TSD
GND
VOUT
13
SLLM
Current Limit
+
+
18
VIN
HG
3
SS
15
14
VOUT
SCP
BOOT
PGND
EN/UVLO
FS
17
6
SLLM
ILIM
3
●PHYSICAL DIMENSIONS
Is+
9
8
Is-
●Pin Number・Pin Name
BD9533
1PIN MARK Lot No.
(UNIT：mm)
HQFN20V
※ Mounting is not recommended to the dotted line part.
Pin
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
-
Pin Name
GND
VCC
ILIM
EN
VIN
SLLM
SCP
ISIS+
PGND
LG
VDD
SW
HG
BOOT
SS
FS
VOUT
VREG
REF
FIN
Please short FIN to the 1PIN
7/20
●Pin Descriptions
・GND(1pin)
This is the ground pin for IC internal circuits. It is equivalent to FIN voltage.
・VCC(2pin)
This is the power supply pin for IC internal circuits, except the FET driver. The maximum circuit current is 900uA. The input
supply voltage range is 4.5V to 5.5V. It is recommended that a 0.1uF bypass capacitor be put in this pin.
・ILIM(3pin)
BD9533EKN detects the voltage between Is+ pin and Is- pin and limits the output current (OCP). Voltage equivalent to 1/10
of the ILIM voltage is the voltage drop of external current sense resistor. A very low current sense resistor or inductor DCR
can also be used for this platform.
・EN(4pin)
When EN pin voltage is at least 2.3V, the status of this switching regulator becomes active. Conversely, the status switches
off when EN pin voltage goes lower than 0.8V and circuit current becomes 10uA.
・VIN(5pin)
The duty cycle is determined by input voltage and output voltage. In other words, the output voltage is affected by input
voltage. Therefore, when VIN voltage fluctuates, the output voltage becomes also unstable. Since the VIN line is also the
input voltage of the switching regulator, stability depends on the impedance of the voltage supply. It is recommended to
establish a bypass capacitor or CR filter suitable for the actual application.
・SLLM(6pin)
This is the switch shift pin for Simple Light Load Mode. The efficiency in SLLM is improved when SLLM pin voltage goes
lower than 0.5V.
・SCP(7pin)
This is the pin to adjust the timer latch time for short circuit protection. The timer circuit is active when the pin voltage
becomes 70% of REF, and the output switches OFF and latched after the specified time. When the UVLO circuit is active or
EN is low, this latch function is cancelled.
・Is-(8pin) ,Is+(9pin)
These pins are connected to both sides of the current sense resistor to detect output current. The voltage drop between Is+
and Is- is compared with the voltage equivalent to 1/10 of ILIM voltage. When this voltage drop reaches the specified
voltage level, the output voltage goes OFF.
・PGND(10pin)
This is the power ground pin connected to the source of the low side FET.
・LG(11pin)
This is the voltage supply to drive the Gate of the low side FET. This voltage swings between VDD and PGND. High-speed
Gate driving for the low side FET is achieved due to the low on-resistance (2 ohm when LG is high, 0.5 ohm when LG is low)
of the driver.
・VDD(12pin)
This is the power supply pin to drive the LOW side FET. It is recommended that a 1uF bypass capacitor be established to
compensate for rush current during the FET ON/OFF transition.
・SW(13pin)
This is the source pin for the high side FET. The maximum absolute ratings are 30V (from GND). SW voltage swings
between VIN and GND.
・HG(14pin)
This is the voltage supply to drive the Gate of the high side FET. This voltage swings between BOOT and SW. High-speed
Gate driving for the high side FET is achieved due to the low on-resistance (3 ohm when HG is high, 2 ohm when HG is low)
of the driver.
・BOOT(15pin)
This is the voltage supply to drive the high side FET. The maximum absolute ratings are 35V (from GND) and 7V (from SW).
BOOT voltage swings between VIN+Vcc and Vcc during active operation.
・SS(16pin)
This is the adjustment pin to set the soft start time. SS voltage is low during standby status. When EN is ON, the soft start
time can be determined by the SS charge current and capacitor between SS-GND. Until SS reaches REF voltage, the
output voltage is equivalent to SS voltage.
・FS(17pin)
This is the pin to adjust the switching frequency based on the resistor value. The frequency range is f=200KHz - 600KHz.
・VOUT(18pin)
This is the output voltage sense pin. It is also possible to adjust the output voltage using external resistor divider based on
the equation, REF≒VOUT.
・VREG(19pin)
This is the reference voltage output pin. The voltage is 2.5V, with 100uA current ability. It is recommended that a 1uF
capacitor (X5R or X7R) be established between VREG and GND. When REF is not adjusted from the external voltage
supply, the REF voltage can be adjusted using the external resistor divider of VREF.
・REF(20pin)
This is the output voltage adjustment pin. It is very convenient for synchronizing external voltage supply. The IC controls the
output voltage (REF≒VOUT).
8/20
●Explanation of Operation
3
TM
The BD9533EKN is a synchronous buck regulator controller incorporating ROHM’s proprietary H Reg CONTROLLA control
system. When VOUT drops due to a rapid load change, the system quickly restores VOUT by extending the TON time interval.
Thus, it serves to improve the regulator’s transient response. Activating the Light Load Mode will also exercise Simple Light
Load Mode (SLLM) control when the load is light, to further increase efficiency.
3
TM
H Reg control
(Normal operation)
When VOUT falls to a threshold voltage (REF), the drop is
3
TM
detected, activating the H Reg CONTROLLA system.
VOUT
REF
TON=
HG
REF
1
×
VIN
f
[sec]・・・(1)
HG output is determined with the formula above.
LG outputs until the status of VOUT is lower than REF
after the status of HG is off.
LG
(VOUT drops due to a rapid load change)
VOUT
When VOUT drops due to a rapid load change, and
the voltage remains below REF after the
programmed TON time interval has elapsed, the
system quickly restores VOUT by extending the TON
time, improving the transient response.
REF
Io
TON+α
HG
LG
(SLLM )
In SLLM (SLLM=0V), SLLM function is operated when
LG pin is OFF and the coil current is lower than 0A
(the current goes from VOUT to SW). And it stops to
output next HG.
When VOUT goes lower than REF voltage again, the
status of HG is ON.
VOUT
REF
HG
LG
0A
9/20
●Timing Chart
• Soft Start Function
Soft start is exercised with the EN pin set high. Current
control takes effect at startup, enabling a moderate
output voltage “ramping start.” Soft start timing and
incoming current are calculated with formulas (2) and
(3) below.
EN
TSS
SS
Soft start time
Tss=
VOUT
REF×Css
2μA(typ)
[sec] ・・・(2)
Incoming current
IIN
IIN=
Co×VOUT
Tss
[A] ・・・(3)
(Css: Soft start capacitor; Co: Output capacitor)
・Timer Latch Type Short Circuit Protection
REF×0.7
Short protection kicks in when output falls to or below
REF X 0.7. When the programmed time period elapses,
output is latched OFF to prevent destruction of the IC.
Output voltage can be restored either by reconnecting
the EN pin or disabling UVLO. Short circuit protection
time is programmed using formula (4) below.
VOUT
TSCP
SCP
Short protection time setting
EN/UVLO
Tscp=
・Over Voltage Protection
VOUT
REF×1.2
HG
LG
Switching
10/20
1.25(V)×CSCP
2μA(typ)
[sec] ・・・(4)
●External Component Selection
1. Inductor (L) selection
The inductor value is a major influence on the output ripple
current. As formula (5) below indicates, the greater the inductor or
the switching frequency, the lower the ripple current.
(VIN-VOUT)×VOUT
ΔIL=
[A]・・・(5)
ΔIL×VIN×f
The proper output ripple current setting is about 30% of maximum
output current.
ΔIL=0.3×IOUTmax. [A]・・・(6)
ΔIL
VIN
IL
VOUT
L
L=
Co
(VIN-VOUT)×VOUT
ΔIL×VIN×f
[H]・・・(7)
(ΔIL: output ripple current; f: switch frequency)
Output ripple current
※Passing a current larger than the inductor’s rated current will cause magnetic saturation in the inductor and decrease
system efficiency. In selecting the inductor, be sure to allow enough margin to assure that peak current does not exceed the
inductor rated current value.
※To minimize possible inductor damage and maximize efficiency, choose a inductor with a low (DCR, ACR) resistance.
2.Output Capacitor (CO) Selection
VIN
VOUT
L
ESR
ESL
Co
When determining the proper output capacitor, be sure to factor in the equivalent
series resistance required to smooth out ripple volume and maintain a stable
output voltage range.
Output ripple voltage is determined as in formula (8) below.
ΔVOUT=ΔIL×ESR+ESL×ΔIL/TON [V]・・・(8)
(ΔIL: Output ripple current; ESR: CO equivalent series resistance,
ESR:equivalent series inductance)
※ In selecting a capacitor, make sure the capacitor rating allows sufficient
margin relative to output voltage. Note that a lower ESR can minimize output
ripple voltage.
Output capacitor
Please give due consideration to the conditions in formula (9) below for output capacity, bearing in mind that output rise time
must be established within the soft start time frame.
Co≦
Tss×(Limit-IOUT)
VOUT
・・・(9)
Tss: Soft start time
Limit: Over current detection
Note: Improper capacitor may cause startup malfunctions.
3. Input Capacitor (Cin) Selection
The input capacitor selected must have low enough ESR resistance to fully
support large ripple output, in order to prevent extreme over current. The formula
for ripple current IRMS is given in (10) below.
VIN
Cin
VOUT
L
IRMS=IOUT×
√VOUT(VIN-VOUT)
[A]・・・(10)
VIN
Co
Where VCC=2×VOUT, IRMS=
IOUT
2
Input Capacitor
A low ESR capacitor is recommended to reduce ESR loss and maximize efficiency.
11/20
4. MOSFET Selection
Loss on the main MOSFET
VIN
Pmain=PRON+PGATE+PTRAN
main switch
=
VOUT
L
VOUT
×RON×IOUT2+Ciss×f×VDD+
VIN
2
VIN ×Crss×IOUT×f
IDRIVE
・・・(11)
(Ron: On-resistance of FET; Ciss: FET gate capacity;
f: Switching frequency Crss: FET inverse transfer function;
IDRIVE: Gate peak current)
Co
synchronous switch
Loss on the synchronous MOSFET
Psyn=PRON+PGATE
=
VIN-VOUT
VIN
×RON×IOUT2+Ciss×f×VDD ・・・(12)
5. Setting Detection Resistance
VIN
The over current protection function detects the output ripple
current peak value. This parameter (setting value) is
determined as in formula (13) below.
L
R
VOUT
ILMIT=
IL
VILIM×0.1
R
Co
[A]・・・(13)
(VILIM: ILIM voltage; R: Detection resistance)
Current limit
When the over current protection is detected by DCR of coil L, this
parameter (setting value) is determined as in formula (14) below.
(Application circuit:P20)
VIN
IL
L
r
RL
C
VOUT
ILMIT=VILIM×0.1×
Co
(RL=
L
r×C
r×C
L
[A]・・・(14)
)
(VILIM:ILIM voltage
Current limit
12/20
RL: the DCR value of coil)
6.Setting frequency
On Time (TON) at steady state is determined by
resistance value connected to FS pin as shown in the
figure. The frequency can be calculated with TON,
input voltage VIN, the reference voltage REF as
follows.
3000
VIN=5V
7V
12V
16V
19V
2500
TON [nsec]
2000
1500
1000
REF
F=
VIN×TON
500
・・・(15)
REF=1.8V
0
0
50
100
RFS [kΩ]
150
200
However, the actual frequency becomes lower than
the formula due to expanded TON time caused by the
rise/fall time of the MOSFET (This rise/fall time is
affected by the switching speed). TON is also
influenced by Dead Time under light load in
continuous mode. In this case the frequency
becomes lower than setting frequency.
The setting frequency noted above is under heavy
load (when the inductor current does not go back to
VIN through the body diodes of the external
MOSFET’s).
Calculated frequency
using TON above
1200
VIN=5V
7V
12V
16V
19V
Frequency [kHz]
1000
800
600
400
200
0
0
50
100
150
200
Resistance [kΩ]
7. Setting standard voltage (REF)
VIN
REF
3
TM
H Reg
CONTROLLA
Outside
voltage
R
It is available to synchronize setting the reference
voltage (REF) with outside supply voltage [V] by using
outside power supply voltage.
Q
S
VOUT
VREG
It is available to set the reference voltage (REF) by the
resistance division value from VREG in case it is not
set REF from an external power supply.
VIN
R1
REF
H3RegTM
CONTROLLA
R2
R
Q
S
REF=
VOUT
13/20
R2
R1+R2
×VREG [V]・・・(16)
8. Setting output voltage
This IC is operated that output voltage is REF≒VOUT.
And it is operated that output voltage is feed back to FB pin in case the output voltage is 0.7V to 2.0V.
VIN
REF
VIN
R
H3RegTM
CONTROLLA
Q
Output
voltage
SLLM
Driver
S
SLLM
Circuit
VOUT
In case the output voltage range is 0.7V to 2.0V.
It is operated that the resistance division value of the output voltage is feed back to VOUT pin in case the output voltage is
more than 2.0V.
output voltage≒
R1+R2
R2
×REF [V]・・・(17)
VIN
REF
VIN
H3RegTM
CONTROLLA
R
Q
Output
voltage
SLLM
Driver
S
SLLM
Circuit
VOUT
R1
R2
In case the output voltage is more than 2.0V.
14/20
●I/O Equivalent Circuit
3pin (ILIM)
4pin (EN)
5pin (VIN)
7pin (SCP)
8pin (Is-)
VCC
6pin (SLLM)
VCC
VCC
9pin (Is+)
VCC
11pin (LG)
VCC
13pin (SW)
VCC
14pin(HG)
15pin (BOOT)
BOOT
16pin (SS)
BOOT
VCC
HG
17pin (FS)
SW
18pin (VOUT)
VCC
BOOT
VDD
19pin (VREG)
VCC
20pin (REF)
VCC
15/20
VCC
HG
●Evaluation Board Circuit (Frequency=300kHz application circuit in Continuous mode/SLLM)
4.5V～25V
VIN
R2
5V
BD9533EKN
0.5V
3
REF
1.8V
20
17
R13
7
16
Ｒ9
REF
R8
Q2
R6
R4
R3
9
Is+
SS
Is- 8
PGND PGND PGND
PGND
R5
VCC
VOUT
18
GND
Part
No
U1
Q1
Q2
D1
D2
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
R1
R2
R3
Value
Company
1uF
10nF
100pF
ROHM
ROHM
ROHM
ROHM
ROHM
KYOCERA
MURATA
MURATA
BD9533EKN
RSS100N03
RSS100N03
RB521S-30
RB051L-40
CM105B105K06A
GRM39X7R103K50
GRM39C0G101J50
10uF
KYOCERA
CM21B106K06
0.1uF
10uF
10uF
1000pF
1500pF
1uF
KYOCERA
KYOCERA
KYOCERA
MURATA
MURATA
KYOCERA
CM05B104K25A
CM316B106M16A
CM316B106M16A
GRM39X7R102K50
GRM39X7R152K50
CM105B105K06A
10uF
KYOCERA
CM21B106M06A
470uF
68KΩ
0Ω
0Ω
SANYO
ROHM
ROHM
ROHM
2R5TPE470ML
MCR03
MCR03
MCR03
VOUT
10
SCP
GND
1.8V/10A
R7
R26
1
PGND
PGND
L1
FS
C1
C2
C11
2
C12
R20
R15
R17
C3
C14
C13
R1
PGND
13
LG 11
ILIM
Q1
C5
SW
ILIM
14
C4
HG
VREG
R25
19
PGND
R24
R12
R14
2.5V
R10
C17
SLLM
VREG
R23
6
R11
C8
R19
15
R22
BOOT
C10
EN
SLLM
PGND
12
R21
4
VDD
C9
R18
VIN
D2
EN
D1
5
C16
VCC
C15
R16
C6
VCC
Part
No
Part name
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
L1
16/20
Value
Company
Part name
0Ω
ROHM
MCR03
5mΩ
0Ω
0Ω
0Ω
0Ω
200kΩ
51kΩ
68kΩ
180kΩ
1kΩ
0Ω
10kΩ
10kΩ
0Ω
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
PMR100
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
0Ω
0Ω
0Ω
ROHM
ROHM
ROHM
MCR03
MCR03
MCR03
1.8uH
SUMIDA
CDEP104-1R8ML
●Evaluation Board Circuit (Frequency=300kHz application circuit for detecting DCR current in Continuous mode/SLLM)
4.5V～25V
VIN
R2
5V
BD9533EKN
R13
7
Ｒ9
16
C1
C2
C11
2
C12
R20
R15
R17
C3
C14
C13
17
1
REF
PGND
C7
10
R4
R3
9
SCP
Is+
SS
Is- 8
PGND PGND PGND
PGND
R5
VCC
VOUT
18
GND
●Evaluation Board Parts List
Part
No
U1
Q1
Q2
D1
D2
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
R1
R2
R3
Value
Company
Part name
1uF
10nF
100pF
ROHM
ROHM
ROHM
ROHM
ROHM
KYOCERA
MURATA
MURATA
BD9533EKN
RSS100N03
RSS100N03
RB521S-30
RB051L-40
CM105B105K06A
GRM39X7R103K50
GRM39C0G101J50
10uF
0.1uF
0.1uF
10uF
10uF
1000pF
1500pF
1uF
KYOCERA
KYOCERA
KYOCERA
KYOCERA
KYOCERA
MURATA
MURATA
KYOCERA
CM21B106K06
CM05B104K25A
CM05B104K25A
CM316B106M16A
CM316B106M16A
GRM39X7R102K50
GRM39X7R152K50
CM105B105K06A
10uF
KYOCERA
CM21B106M06A
330uF
68KΩ
0Ω
0Ω
SANYO
ROHM
ROHM
ROHM
6TPB330M
MCR03
MCR03
MCR03
C5
R6
C4
Q2
C17
R8
FS
GND
VOUT
L1
R26
20
R1
PGND
R25
REF
PGND
Q1
13
LG 11
ILIM
PGND
R24
SW
14
R10
R23
R12
R14
HG
VREG
ILIM
3
R11
SLLM
VREG
19
15
R21
6
R22
BOOT
R19
C10
EN
SLLM
PGND
12
C9
4
VDD
D2
R18
VIN
D1
EN
C8
5
C16
VCC
C15
Ｒ16
C6
VCC
Part
No
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
L1
17/20
Value
Company
Part name
0Ω
1kΩ
ROHM
ROHM
MCR03
MCR03
0Ω
0Ω
0Ω
0Ω
51kΩ
200kΩ
68kΩ
180kΩ
1kΩ
0Ω
10kΩ
10kΩ
0Ω
0Ω
0Ω
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
ROHM
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
MCR03
0Ω
ROHM
MCR03
3.3uH
NEC/TOKIN
MPLC0730L3R3
●Operation Notes
1.
Absolute maximum ratings
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can
break down the devices, thus making impossible to identify breaking mode, such as a short circuit or an open circuit. If any
over rated values will expect to exceed the absolute maximum ratings, consider adding circuit protection devices, such as
fuses.
2. Connecting the power supply connector backward
Connecting of the power supply in reverse polarity can damage IC. Take precautions when connecting the power supply
lines. An external direction diode can be added.
3. Power supply lines
Design PCB layout pattern to provide low impedance GND and supply lines. To obtain a low noise ground and supply line,
separate the ground section and supply lines of the digital and analog blocks. Furthermore, for all power supply terminals to
ICs, connect a capacitor between the power supply and the GND terminal. When applying electrolytic capacitors in the
circuit, not that capacitance characteristic values are reduced at low temperatures.
4. GND voltage
The potential of GND pin must be minimum potential in all operating conditions.
5. Thermal design
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions.
6. Inter-pin shorts and mounting errors
Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any
connection error or if pins are shorted together.
7. Actions in strong electromagnetic field
Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to
malfunction.
8. ASO
When using the IC, set the output transistor so that it does not exceed absolute maximum ratings or ASO.
9. Thermal shutdown circuit
The IC incorporates a built-in thermal shutdown circuit (TSD circuit). The thermal shutdown circuit (TSD circuit) is designed
only to shut the IC off to prevent thermal runaway. It is not designed to protect the IC or guarantee its operation. Do not
continue to use the IC after operating this circuit or use the IC in an environment where the operation of this circuit is
assumed.
TSD on temperature [°C] (typ.)
Hysteresis temperature [°C] (typ.)
BD9533EKN
175
15
10. Testing on application boards
When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.
Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting it to or
removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an antistatic
measure. Use similar precaution when transporting or storing the IC.
18/20
11. Regarding input pin of the IC
This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated.
P-N junctions are formed at the intersection of these P layers with the N layers of other elements, creating a parasitic diode
or transistor. For example, the relation between each potential is as follows:
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes can occur inevitable in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Accordingly, methods by which parasitic diodes
operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be used.
Resistor
Transistor (NPN)
Pin A
Pin B
C
Pin B
B
E
Pin A
N
P+
N
P
P+
N
Parasitic
element
N
P+
P substrate
Parasitic element
GND
B
N
P+
P
N
C
E
Parasitic
element
P substrate
Parasitic element
GND
GND
GND
Other adjacent elements
Fig. 37 Example of IC structure
12. Ground Wiring Pattern
When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns,
placing a single ground point at the ground potential of application so that the pattern wiring resistance and voltage
variations caused by large currents do not cause variations in the small signal ground voltage. Be careful not to change the
GND wiring pattern of any external components, either.
19/20
●Type Designations (Selections) for Ordering
B
D
9
5
3
Product name
3
E
K
Package type
・BD9533
N
―
E
2
Taping type name
E2= Embossed carrier tape
・EKN : HQFN20V
HQFN20V
<Tape and Reel information>
<Dimension>
(2.1)
4.2±0.1
4.0±0.1
0.5
(1.1)
10
(2.1)
20
6
5
Embossed carrier tape(with dry pack)
Quantity
2500pcs
E2
Direction
of feed
(The direction is the 1pin of product is at the upper left when you hold
reel on the left hand and you pull out the tape on the right hand)
5)
.3
(0
3−
1
0.22±0.05
.2
2)
11
(0
4.0±0.1
0.05
0.1
0.6 −+0.3
1234
1234
1234
1234
1234
1234
0.22±0.05
)
.5
(0
0.03
0.02 −+0.02
0.95MAX
4.2±0.1
15
16
Tape
0.05
Reel
(Unit:mm)
1pin
Direction of feed
※When you order , please order in times the amount of package quantity.
20/20
Catalog No.08T441A '08.9 ROHM ©
Appendix
Notes
No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM
CO.,LTD.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter "Products"). If you
wish to use any such Product, please be sure to refer to the specifications, which can be obtained from ROHM
upon request.
Examples of application circuits, circuit constants and any other information contained herein illustrate the
standard usage and operations of the Products. The peripheral conditions must be taken into account
when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document. However, should
you incur any damage arising from any inaccuracy or misprint of such information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and examples
of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to
use or exercise intellectual property or other rights held by ROHM and other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the use of such technical information.
The Products specified in this document are intended to be used with general-use electronic equipment
or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
The Products are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a Product may fail or
malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard against the
possibility of physical injury, fire or any other damage caused in the event of the failure of any Product, such as
derating, redundancy, fire control and fail-safe designs. ROHM shall bear no responsibility whatsoever for your
use of any Product outside of the prescribed scope or not in accordance with the instruction manual.
The Products are not designed or manufactured to be used with any equipment, device or system
which requires an extremely high level of reliability the failure or malfunction of which may result in a direct
threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment,
aerospace machinery, nuclear-reactor controller, fuel-controller or other safety device). ROHM shall bear
no responsibility in any way for use of any of the Products for the above special purposes. If a Product is intended to be used for any such special purpose, please contact a ROHM sales representative before purchasing.
If you intend to export or ship overseas any Product or technology specified herein that may be controlled under
the Foreign Exchange and the Foreign Trade Law, you will be required to obtain a license or permit under the Law.
Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact your nearest sales office.
ROHM Customer Support System
www.rohm.com
Copyright © 2009 ROHM CO.,LTD.
THE AMERICAS / EUROPE / ASIA / JAPAN
Contact us : webmaster @ rohm.co. jp
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Appendix-Rev4.0