October 28, 2003 Ver. 4
Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator In Series plus Voltage Detector
Preliminary
!
Input Voltage Range
2.4V ~ 6.0V
!
APPLICATIONS
!
Output Voltage Range
DC/DC
0.9 ~ 4.0V (
2%)
"
CD-R / RW, DVD
VR
0.9 ~ 4.0V (
2%)
"
HDD
VD
0.9 ~ 5.0V (
2%)
"
PDAs, portable communication modem
!
Switching Frequency
300kHz, 600kHz, 1.2MHz
"
Cellular phones
!
Output Current
DC/DC
800mA
"
Palmtop computers
VR
600mA
"
Cameras, video recorders
!
Ultra Small Packages
SOP-8
!
Ceramic Capacitor Compatible
!
GENERAL DESCRIPTION
!
FEATURES
Input Voltage Range :
2.4V ~ 6.0V
Load Capacitors :
Ceramic Capacitors Compatible
(Low ESR Capacitors)
VD Function :
Detects output voltage from the VDOUT pin
while sensing either VDD, DCOUT,
or VROUT internally.
Nch Open Drain Output
<DC/DC Converter>
Output Voltage Range : 0.9 ~ 4.0V (Accuracy
2%)
Output Current :
800mA
Controls :
PWM Control
Oscillation Frequency : 300kHz, 600kHz, 1.2MHz
<Regulator>
Output Voltage Range : 0.9 ~ 4.0V (Accuracy
2%)
Current Limit
600mA
Dropout Voltage :
240mV @ IOUT=300mA (VOUT=2.8V)
High Ripple Rejection
60dB @1kHz (VOUT=2.8V)
!
TYPICAL APPLICATION CIRCUIT
!
TYPICAL PERFORMANCE CHARACTERISTICS
XC9510 Series
PWM, PWM / PFM Automatic
Switching External
The XC9510 series consists of a step-down DC/DC converter and a
high-speed LDO regulator connected in series with the DC/DC
converter's output. A voltage detector is also built-in. A highly
efficient, low noise output is possible since the regulator is stepped-
down further from the DC/DC output.
The DC/DC converter block incorporates a P-Channel driver transistor
and a synchronous N-Channel switching transistor. With an external
coil, diode and two capacitors, the XC9510 can deliver output currents
up to 800mA at efficiencies over 90%. The XC9510 is designed for
use with small ceramic capacitors.
A choice of three switching frequencies are available, 300 kHz, 600
kHz, and 1.2 MHz.
Output voltage settings for the DC/DC and VR are set-up internally in
0.1V steps within the range of 0.9V to 4.0V (
2.0%). For the VD, the
range is of 0.9V to 5.0V (
2.0%).
The soft start time of the series is internally set to 5ms. With the built-
in U.V.L.O. (Under Voltage Lock Out) function, the internal P-channel
driver transistor is forced OFF when input voltage becomes 1.4 V or
lower.
The operational states of the DC/DC and the regulator blocks can be
changed by inputting three kinds of voltage level via the CE/MODE pin.
The functions of the MODE pin can be selected via the external control
pin to switch the DC/DC control mode and the disable pin to shut down
the regulator block.
SOP-8 (Top View)
1
2
3
4
8
7
5
6
VDD
CE/
MODE
AGND
LX
DCOUT
VROUT
VDOUT
PGND
CIN
L
CL1
CL2
DCOUT
VROUT
SD
(
)
Semiconductor Ltd.
XC9510Hxxxx
0
10
20
30
40
50
60
70
80
90
100
0.1
1
10
100
1000
DC/DC Output Current IDOUT
VR Output Current IROUT (mA)
E
f
f
i
ci
e
n
cy E
F
F
I
(
%
)
VIN=5.0V, Topr=25
O
C, L:4.7uH(CDRH4D28C),
CIN:4.7uF(ceramic), CL1:10uF(ceramic), CL2:1uF(ceramic)
DC/DC Efficiency (DCOUT:3.4V, 1.2MHz), VR Efficiency (VROUT:3.0V)
PWM/PFM switching control
PWM control
Data Sheet
1
Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator In Series plus Voltage Detector
Preliminary
!
PIN CONFIGURATION
!
PIN ASSIGNMENT
1
2
3
4
5
6
7
8
!
SELECTION GUIDE
"
Ordering Information
XC9510
123456
The input for the voltage regulator block comes from the DC/DC.
Control Methods and MODE pins, the VD Sense pin (See the chart below)
Setting voltage and specifications of each DC/DC, VR, and VD (Based on the internal standard)
Oscillation Frequency of DC/DC :
300kHz
600kHz
1.2MHz
Package Type :
SOP-8
Device Orientation :
Embossed Tape : Standard feed
Embossed Tape : Reverse feed
$
Control Methods, CE/MODE Pin, VDSENSE
SOP-8 (Top View)
C
CE/MODE PINS
(L LEVEL)
VD
SENSE
K
D
E
F
H
A
VR : OFF
DC/DC CONTROL
METHODS
5
4
3
6
C
CE/MODE PINS
(H LEVEL)
L
PWM, PFM/PWM
Manual Switch
SERIES
1
23
1
B
R
L
6
XC9510
PWM Control
S
DESIGNATOR
DESCRIPTION
SYMBOL
Chip Enable / MODE Switch
Power Supply
VD Output
Analog Ground
CE/MODE
VDD
VDOUT
AGND
Switch
LX
DCOUT
DC/DC Output
VROUT
VR Output
PIN
NUMBER
FUNCTION
PIN NAME
Power Ground
PGND
XC9510 Series
VROUT
PFM/PWM
Automatic Switch
-
VR : ON
PWM Control
-
CE/MODE PINS
(M LEVEL)
Stand-by Mode
(Except for VD)
VDD
DCOUT
VROUT
VDD
DCOUT
VROUT
VDD
DCOUT
Semiconductor Ltd.
PGND 1
CE/MODE 2
VDD 3
VDOUT 4
8 LX
7 DCOUT
6 VROUT
5 AGND
Data Sheet
2
Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator In Series plus Voltage Detector
Preliminary
!
PACKAGING INFORMATION
$
SOP-8
!
BLOCK DIAGRAM
* Diodes shown in the above circuits are protective diodes.
!
ABSOLUTE MAXIMUM RATINGS
Ta=25
O
C
(*1) IOUT = Pd / (VIN - VOUT) when PC board mounting.
(*2) Package power dissipation
650
Pd
Topr
- 40 ~ + 85
VDD Pin Voltage
DCOUT Pin Voltage
VROUT Pin Voltage
VDOUT
- 0.3 ~ VDD + 0.3
VDOUT Pin Voltage
XC9510 Series
PARAMETER
Storage Temperature Range
LX Pin Voltage
Continuous Power Dissipation (*1)
Operating Temperature Range
CE/MODE Pin Voltage
SOP-8
V
Tstg
mW
O
C
- 0.3 ~ VDD + 0.3
V
- 55 ~ + 125
O
C
SYMBOL
RATINGS
UNITS
AVDD
- 0.3 ~ 6.5
V
V
- 0.3 ~ VDD + 0.3
V
VROUT
- 0.3 ~ VDD + 0.3
V
DCOUT
LX
CE/MODE
- 0.3 ~ VDD + 0.3
Semiconductor Ltd.
+
-
Vref with
soft start
PWM/PFM
Controller
Phase
Compensation
+
-
logic
Buffer,
Driver
Current Limit &
Feedback
R amp Wave
Generator,
OSC
DCOUT
VDD
-
+
U.V.L.O.
LX
VROUT
AGND
+
-
Current
Li mi t
Vref
PGND
CE/MODE
ON/OFF&
MODE
CONTROL
eac h
circuit
+
-
VDOUT
Vref
SENSE
(VDD or DCOUT or VROUT)
Data Sheet
3
Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator In Series plus Voltage Detector
Preliminary
!
ELECTRICAL CHARACTERISTICS
XC9510HxxCSx
$
Common Characteristics
$
DC/DC Converter (2.2V product)
$
Regulator (1.8V product)
-
VDD-1.2
V
3
CE 'M' Level Voltage
VCEM
-
-
100
-
IROUT=30mA
-40
O
C<Topr<85
O
C
Short-Circuit Current
-
IROUT=30mA
-
-
dB
VROUT(T)+1V<VIN<6V
VROUT=VROT(E)x0.9
Connected to the external components,
VIN=CE=5.0V,
Short DCOUT by 1
resistor
-
8
1.800
-
1.764
IROUT=30mA
TEST CIRCUIT
UNITS
3
3
-
Temperature Characteristics
!
Topr
"
VOUT
Output Voltage
!
VOUT
-
100
IDOUT=30mA
-40
O
C<Topr<85
O
C
Efficiency (note 4)
Stand-by Current (note 1)
ISTB
Supply Current 2
Supply Current 1
PARAMETER
SYMBOL
CE 'H' Level Voltage
VCEH
VIN
VUVLO
U.V.L.O. Voltage (note 2)
CE 'H' Level Current
ICEH
!
VOUT
PARAMETER
Output Voltage
SYMBOL
CE 'L' Level Current
ICEL
ILIM1
Current Limit
Current Limit
Line Regulation
ILIM2
Output Voltage
VROUT(E)
Maximum Output Current
IMAX2
Dropout Voltage 2
Vdif 2
DCOUT
XC9510 Series
VIN=6.5V, CE=0V
TEST CIRCUIT
2.156
30
-
-
0.6
1.78
1.00
85
-
mV
2
15
50
mV
2
-
mA
600
-
0.2
-
%/V
2
-
Load Regulation
!
VROUT
Dropout Voltage 1 (note 6)
Vdif 1
!
VIN
"
VOUT
-
1mA<IROUT<100mA
IROUT=30mA
IROUT=100mA
Soft Start Time
TSS
-
PARAMETER
SYMBOL
MIN.
Connected to the external components,
CE=0V
"
VIN, IDOUT=1mA
Latch Time (note 5)
Tlat
CONDITIONS
EFFI
3
Maximum Output Current
IMAX1
800
%
Connected to the external components,
IDOUT=100mA
6
A
LX SW 'Low' On Resistance
RLXL
-
LX SW 'High' On Resistance
(note 3)
RLXH
-
DCOUT=0V, LX=VIN-0.05V
0.5
3
1.20
1.38
MHz
-
-
4
3
4
0
3
MAXDUTY
1.02
FOSC
DCOUT=0V
100
PFM Duty Ratio
CONDITIONS
Minimum Duty Ratio
MINDUTY
Oscillation Frequency
Maximum Duty Ratio
PFMDUTY
Input Voltage Range
VIN=CE=DCOUT=5.0V
%
-
Connected to the external components,
No Load
DCOUT=VIN
-
-
0.5
-
-
-
-
1.2
-
-
TYP.
MAX.
-
90
-
-
5
1.836
200
2
Output Voltage
5
3
ppm
/
O
C
ISHORT
-
30
VROUT=VSS
-
60
ppm
/
O
C
Temperature Characteristics
!
Topr
"
VOUT
PSRR
!
VOUT
-
VIN={VOUT(T) + 1.0} VDC + 0.5Vp-pAC
IROUT=30mA, f=1kHz
Ripple Rejection Rate
MAX.
UNITS
TEST CIRCUIT
V
3
mA
2
mS
Ta=25
O
C
-
300
-
1
V
6.0
1
2.4
TYP.
IDD2
-
0.6
2.5
VIN=CE=5.0V, DCOUT=0V
MIN.
IDD1
-
240
-
-
-
1
3
V
1.40
V
3
VDD
-
CE 'L' Level Voltage
VCEL
VSS
-
0.25
1
- 0.1
-
0.1
21
- 0.1
-
0.1
38
30
MIN.
2
Ta=25
O
C
mA
3
mV
7
7
2
2
mS
CONDITIONS
Connected to the external components,
IDOUT=10mA
TYP.
MAX.
2.200
2.244
UNITS
-
%
V
V
mA
%
Ta=25
O
C
Connected to the external components,
IDOUT=30mA
1
Semiconductor Ltd.
Data Sheet
4
Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator In Series plus Voltage Detector
Preliminary
!
ELECTRICAL CHARACTERISTICS (Continued)
$
Detector (2.7V product)
Test Conditions :
Unless otherwise stated;
* VROUT(T) : Setting Output Voltage
DC/DC : VIN=3.6V [@ DCOUT:2.2V]
VD : VIN=6.0V
VR : VIN = VROUT(T) + 1.0 (V) [When VROUT(T) <1.4V, VIN =2.4V]
note 1 : VD operates when in stand-by mode.
note 2 : Including hysteresis operating voltage range.
note 3 : On resistance = 0.05V / ILX
note 4 : EFFI = { ( Output Voltage x Output Current ) / ( Input Voltage x Input Current) } x 100
note 5 : Time until it short-circuits DCOUT with GND through 1
of resistance from a state of operation
and is set to DCOUT=0V from current limit pulse generating.
note 6 : Vdif = (VIN1
(note 7)
- VROUT1
(note 8 )
)
note 7 : VIN 1 = The input voltage when VROUT1 appears as input voltage is gradually decreased.
note 8 : VROUT1 = A voltage equal to 98% of the output voltage whenever an amply stabilized IOUT {VROUT(T) + 1.0V} is input.
-
-
mA
9
Ta=25
O
C
XC9510 Series
CONDITIONS
PARAMETER
SYMBOL
VDOUT=0.5V
VD Output Current
IVD
1
V
8
UNITS
MIN.
TYP.
MAX.
2.700
5
8
2.646
3
2.754
-
TEST CIRCUIT
-
%
Hysteresis Range
VHYS
Detect Voltage
VDF
!
Topr
"
VDF
Output Voltage
!
VDF
-40
O
C<Topr<85
O
C
100
-
ppm
/
O
C
8
Temperature Characteristics
Semiconductor Ltd.
Data Sheet
5
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