XC9509A [TOREX]

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector; 与内置LDO稳压器，同步降压型DC / DC转换器并联加电压检测器


型号：	XC9509A
厂家：	Torex Semiconductor
描述：	Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector 与内置LDO稳压器，同步降压型DC / DC转换器并联加电压检测器转换器稳压器
文件：	总9页 (文件大小：98K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

September 30, 2003 Ver. 1

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢀInput Voltage Range

ꢀOutput Voltage Range

2.4V ~ 6.0V

ꢁAPPLICATIONS

DC/DC

0.9 ~ 4.0V (±2%)

ꢂHDD

0.9 ~ 4.0V (±2%)

0.9 ~ 5.0V (±2%)

ꢂCD-R / RW, DVD

ꢂPDAs, portable communication modem

ꢂCellular phones

ꢀSwitching Frequency

ꢀOutput Current

300kHz, 600kHz, 1.2MHz

DC/DC

600mA

200mA

ꢂPalmtop computers

ꢂCameras, video recorders

ꢀUltra Small Packages

MSOP-10, USP-10

ꢀCeramic Capacitor Compatible

ꢁGENERAL DESCRIPTION

ꢁFEATURES

Input Voltage Range :

Load Capacitors :

2.4V ~ 6.0V

The XC9509 series consists of a step-down DC/DC converter and a

high-speed LDO regulator connected in parallel with the DC/DC

converter's output. A voltage detector is also built-in. Since the input

for the LDO voltage regulator block comes from the input power supply,

it is suited for use with various applications.

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 XC9509 can deliver output currents

up to 600mA at efficiencies over 90%. The XC9509 is designed for

use with small ceramic capacitors.

Ceramic Capacitors Compatible

(Low ESR Capacitors)

Sense internally either

VDD, DCOUT, or VROUT.

Nch Open Drain Output

VD Function :

Output Voltage Range :

Output Current :

0.9 ~ 4.0V (±2%)

A choice of three switching frequencies are available, 300 kHz,

600 kHz, and 1.2 MHz.

600mA

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 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

either the DC/DC block or the regulator block.

Controls :

PWM Control

PWM, PWM / PFM Automatic

Switching External

Oscillation Frequency :

300kHz, 600kHz, 1.2MHz

Output Voltage Range :

Current Limit

0.9 ~ 4.0V (±2%)

300mA

Dropout Voltage :

High Ripple Rejection

80mV @ IOUT=100mA (VOUT=2.8V)

60dB @1kHz (VOUT=2.8V)

ꢁTYPICAL APPLICATION CIRCUIT

ꢁTYPICAL PERFORMANCE CHARACTERISTICS

XC9509Hxxxx

VIN=3.6V, Topr=25 C, L:4.7uH(CDRH4D28C)

CIN:4.7uF(ceramic), CL1:10uF(ceramic), CL2: 1uF(ceramic)

100

CL1

DC/DC Efficiency

DCOUT

VROUT

PGND

(DCOUT:2.2V, 1.2MHz)

DCOUT

PVDD

AVDD

VDOUT

VROUT

MODE

CL2

AGND

CIN1

CIN2

MSOP-10

(TOP VIEW)

PWM/PFM Switching Control

PWM Control

0.1

100

1000

DC/DC Output Current IDOUT (mA)

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁPIN CONFIGURATION

ꢁPIN ASSIGNMENT

NUMBER

PIN NAME

FUNCTION

PGND1

CE 2

10 LX

9 DCOUT

8 VROUT

7 MODE

6 AGND

PVDD3

AVDD4

VDOUT5

PGND

Power Ground

Chip Enable

Power Supply 1

Power Supply 2

VD Input

PVDD

AVDD

VDOUT

AGND

MODE

VROUT

DCOUT

MSOP-10(TOP VIEW)

10 LX

PGND1

CE 2

Analog Ground

Mode Switch

VR Output

9 DCOUT

8 VROUT

7 MODE

6 AGND

PVDD3

AVDD4

VDOUT5

DC/DC Output

Switch

USP-10(TOP VIEW)

ꢁSELECTION GUIDE

ꢂ Ordering Information

XC9509 123456

DESIGNATOR SYMBOL

The input for the voltage regulator block comes from VDD.

DESCRIPTION

Control Methods, the MODE pin, 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 :

MSOP-10

USP-10

Device Orientation :

Embossed Tape : Standard Feed

Embossed Tape : Reverse Feed

ꢃControl Methods, MODE Pins, and VD SENSE Pins

SERIES

DC/DC CONTROL METHODS

MODE PINS (H LEVEL)

VR : OFF

MODE PINS (L LEVEL)

VR : ON

VD SENSE

VDD

DCOUT

VROUT

VDD

PWM Control

DC/DC : OFF

DC/DC : ON

PWM Control

XC9509

DCOUT

VROUT

VDD

PWM, PFM/PWM Manual Switch

PFM/PWM Auto Switch

DCOUT

VROUT

* The XC9509A to F series' MODE pin switches either the regulator block or DC/DC block to stand-by mode.

When the CE mode is off, every function except for the VD function enters into stand-by mode.

(The MODE pin does not operate independently.)

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁPACKAGING INFORMATION

0.15+0.01

ꢃMSOP-10

ꢃUSP-10

2.7+0.05

0.30

0.15

3.00+0.10

* Soldering fillet surface is not formed

because the sides of the pins are not

plated.

2.30

(0.5)

0.2+0.05

(0.5

)

(0.2)

ꢁBLOCK DIAGRAM

PV DD

DCOUT

Phase

Compensation

Buffer,

Driver

Logic

Current Limit

Feedback

Vref with

soft start

PWM/PFM

Controller

Ramp Wave

Generator,

OSC

ON/OFF,

CONTROL

each

circuit

PGND

MODE

CONTROL

each

circuit

AVDD

VROUT

Current

Limit

U.V.L.O

VDOUT

Vref

SENSE

(VDD or DCOUT or VROUT)

AGND

* Diodes shown in the above circuits are protective diodes.

ꢁABSOLUTE MAXIMUM RATINGS

Ta=25^OC

UNITS

PARAMETER

AVDD Pin Voltage

PVDD Pin Voltage

DCOUT Pin Voltage

VROUT Pin Voltage

VDOUT Pin Voltage

LX Pin Voltage

SYMBOL

AVDD

PVDD

DCOUT

VROUT

VDOUT

RATINGS

- 0.3 ~ 6.5

- 0.3 ~ VDD + 0.3

350

CE Pin Voltage

MODE Pin Voltage

MODE

MSOP-10

USP-10

Continuous Power Dissipation (*1)

120 (*2)

^OC

Operating Temperature Range

Storage Temperature Range

Topr

Tstg

- 40 ~ + 85

- 55 ~ + 125

(*1) IOUT = Pd / (VIN - VOUT) when PC board mounting.

(*2) Package power dissipation

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁELECTRICAL CHARACTERISTICS

XC9509HxxCAx

Ta=25^OC

UNITS ^{TEST CIRCUIT}

ꢃ Common Characteristics

PARAMETER

Supply Current 1

SYMBOL

IDD1

IDD2

ISTB

VIN

CONDITIONS

VIN=CE=DCOUT=5.0V

VIN=CE=5.0V, DCOUT=0V

VIN=6.5V, CE=0V

MIN.

TYP.

MAX.

300

µΑ

Supply Current 2

240

Stand-by Current (note 1)

Input Voltage Range

U.V.L.O. Voltage (note 2)

CE 'H' Level Voltage

CE 'L' Level Voltage

CE 'H' Level Current

CE 'L' Level Current

MODE 'H' Level Voltage

MODE 'L' Level Voltage

MODE 'H' Level Current

MODE 'L' Level Current

0.6

2.5

2.4

1.00

0.6

VSS

- 0.1

0.6

VSS

- 0.1

6.0

VUVLO

VCEH

VCEL

ICEH

ICEL

VMH

VML

1.40

1.78

VDD

0.25

0.1

µΑ

0.1

VDD

0.25

0.1

IMH

µΑ

IML

0.1

Ta=25^OC

ꢃ DC/DC Converter (2.2V product)

PARAMETER

SYMBOL

CONDITIONS

MIN.

TYP.

MAX.

2.244

UNITS ^{TEST CIRCUIT}

Connected to the external components,

IDOUT=30mA

Output Voltage

DCOUT

2.156

2.200

Connected to the external components,

IDOUT=10mA

Oscillation Frequency

FOSC

1.02

1.20

1.38

MHz

Maximum Duty Ratio

Manimum Duty Ratio

MAXDUTY

MINDUTY

DCOUT=0V

100

DCOUT=VIN

Connected to the external components,

No Load

PFM Duty Ratio

PFMDUTY

RLXH

LX SW 'High' On Resistance

(note 3)

DCOUT=0V, LX=VIN-0.05V

0.5

Ω

LX SW 'Low' On Resistance

Maximum Output Current

Current Limit

RLXL

IMAX1

ILIM1

600

0.5

Ω

1.2

Connected to the external components,

IDOUT=100mA

Efficiency (note 4)

EFFI

±100

! VOUT

ppm

/^OC

Output Voltage

IDOUT=30mA

-40^OC<Topr<85^OC

! Topr

ꢂ

VOUT

Temperature Characteristics

Connected to the external components,

CE=0V"VIN, IDOUT=1mA

Connected to the external components,

VIN=CE=5.0V,

Soft Start Time

TSS

Latch Time (note 5)

Tlat

Short DCOUT by 1Ω resistor

Ta=25^OC

ꢃ Regulator (1.8V product)

PARAMETER

SYMBOL

CONDITIONS

IROUT=30mA

MIN.

TYP.

1.800

MAX.

UNITS ^{TEST CIRCUIT}

Output Voltage

Maximum Output Current

Load Regulation

VROUT(E)

IMAX2

1.764

1.836

200

! VROUT

1mA<IROUT<100mA

Dropout Voltage 1 (note 6)

Dropout Voltage 2

Vdif 1

Vdif 2

IROUT=30mA

IROUT=100mA

! VOUT

IROUT=30mA

Line Regulation

0.2

%/V

! VIN

ꢂ

VOUT

VROUT(T)+1V<VIN<6V

Current Limit

ILIM2

VROUT=VROUT(E)x0.9

VROUT=VSS

300

Short-Circuit Current

ISHORT

VIN={VOUT(T) + 1.0} VDC + 0.5Vp-pAC

IROUT=30mA, f=1kHz

Ripple Rejection Rate

PSRR

! VOUT

ppm

/^OC

Output Voltage

IDOUT=30mA

-40^OC<Topr<85^OC

±100

! Topr

ꢂ

VOUT

Temperature Characteristics

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁELECTRICAL CHARACTERISTICS (Continued)

ꢃ Detector (2.7V product)

Ta=25^OC

UNITS ^{TEST CIRCUIT}

PARAMETER

Detect Voltage

SYMBOL

CONDITIONS

MIN.

2.646

TYP.

MAX.

VDF

VHYS

IVD

2.700

2.754

Hysteresis Range

VD Output Current

Output Voltage

VDOUT=0.5V

! VDF

ppm

/^OC

-40^OC<Topr<85^OC

±100

! Topr VDF

ꢂ

Temperature Characteristics

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 1Ω 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.

)

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁTEST CIRCUITS

Circuit

Supply Current, Stand-by Current,

CE Current, MODE Current

Circuit

Output Voltage (VR), Load Stability, Dropout Voltage,

CE Current (MODE Current)

PGND

1 0

PGND

1 0

DCOUT : VIN or GND

CE : VIN or GND

DCOUT

VROUT

MODE

AGND

DCOUT

PVDD

AVDD

VDOUT

PVDD

AVDD

VROUT

MODE

MODE:

VIN or GND

VDOUT

AGND

IROUT

CIN:1.0uF

(ceramic)

CIN

(ceramic)

: 4.7uF

CL:1.0uF(ceramic,

2.2uF(ceramic,

VROUT>1.5V)

VROUT<1.5V)

Circuit 3 Output Voltage (DC/DC) Oscillation Frequency,

U.V.L.O. Voltage, Soft start Time, Latch Time, CE Voltage,

(PFM Duty Cycle), (MODE Voltage)

Circuit

Minimum Duty Cycle, Maximum Duty Cycle

PGND

1 0

PGND

DCOUT

VROUT

MODE

AGND

1 0

CE : VIN

DCOUT

VROUT

MODE

AGND

MODE:

VIN or GND

PVDD

AVDD

VDOUT

PVDD

AVDD

VDOUT

200Ω

IDOUT

: 10uF

(ceramic)

CIN

(ceramic)

1.0uF

CIN

(ceramic)

: 4.7uF

FOSC

300kHz

600kHz

1.2MHz

22uH

10uH

4.7uH

Circuit

Lx ON Resistance

Circuit

Current Limit 1 (DC/DC)

PGND

1 0

PGND

DCOUT

VROUT

MODE

AGND

1 0

CE : VIN

DCOUT

VROUT

MODE

AGND

MODE:

VIN or GND

PVDD

AVDD

VDOUT

PVDD

AVDD

VDOUT

IDOUT

CIN

(ceramic)

: 4.7uF

CIN

(ceramic)

: 1.0uF

Circuit

Current Limit 2 (VR), Short Protection (VR)

Circuit

Detect Voltage, Release Voltage

PGND

1 0

VD_SENSE

(DCOUT or VROUT)

PGND

1 0

MODE

VIN or GND

CE : VSS

CE : VIN

DCOUT

VROUT

MODE

AGND

PVDD

AVDD

VROUT

MODE

PVDD

AVDD

VDOUT

AGND

CIN:1uF

200k Ω

CL:1.0uF(ceramic)

CIN

: 4.7uF

(ceramic)

Circuit

Detect Voltage, Release Voltage

VD_SENSE

(DCOUT or VROUT)

PGND

LX 1 0

VSS

DCOUT

PVDD

AVDD

VDOUT

VROUT

MODE

AGND

CIN:1uF

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁTYPICAL APPLICATION CIRCUIT

FOSC

1.2MHz

600kHz

300kHz

CL1

4.7µH (CDRH4D28C, SUMIDA)

10µH (CDRH4D28C, SUMIDA)

22µH (CDRH4D28C, SUMIDA)

DCOUT

VROUT

PGND

DCOUT

PVDD

AVDD

VDOUT

VROUT

MODE

CL2

AGND

CIN1

CIN

CL1

CL2

: 4.7µF (ceramic, TAIYO-YUDEN)

: 10µF (ceramic, TAIYO-YUDEN)

CIN2

MSOP-10

(TOP VIEW)

1µF (ceramic, TAIYO-YUDEN), VROUT>1.5V

: 2.2µF (ceramic, TAIYO-YUDEN), VROUT<1.5V

ꢁOPERATIONAL EXPLANATION

The XC9509 series consists of a synchronous step-down DC/DC converter, a high speed LDO voltage regulator, and a voltage detector.

ꢃDC/DC Converter

The series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output

voltage adjustment resistors, driver transistor, synchronous switch, current limiter circuit, U.V.L.O. circuit and others. The series ICs compare,

using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the VOUT pin through split

resistors. Phase compensation is performed on the resulting error amplifier output, to input a signal to the PWM comparator to determine the

turn-on time during PWM operation. The PWM comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp

wave from the ramp wave circuit, and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle.

This process is continuously performed to ensure stable output voltage. The current feedback circuit monitors the P-channel MOS driver

transistor current for each switching operation, and modulates the error amplifier output signal to provide multiple feedback signals. This

enables a stable feedback loop even when a low ESR capacitor, such as a ceramic capacitor, is used, ensuring stable output voltage.

< Reference Voltage Source >

The reference voltage source provides the reference voltage to ensure stable output voltage of the DC/DC converter.

< Ramp Wave Circuit >

The ramp wave circuit determines switching frequency. The frequency is fixed internally and can be selected from 300kHz, 600 kHz and 1.2

MHz. Clock pulses generated in this circuit are used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal

circuits.

< Error Amplifier >

The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback voltage divided by the

internal split resistors. When a voltage lower than the reference voltage is fed back, the output voltage of the error amplifier increases. The gain

and frequency characteristics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer.

< PWM/PFM >

The PWM mode of the XC9509A to F series are controlled on a specified frequency from light loads through the heavy loads. Since the

frequency is specified, the composition of a noise filter etc. becomes easy. However, the efficiency at the time of the light load may become

low. The XC9509H to L series can switch in any timing between PWM control and PWM/PFM automatic switching control. The series can not

control only PFM mode. If needed, the operation can be set on a specified frequency; therefore, the control of the noise etc. is possible and the

high efficiency at the time of the light load during PFM control mode is possible. With the automatic PWM/PFM switching control function, the

series ICs are automatically switched from PWM control to PFM control mode under light load conditions. If during light load conditions the coil

current becomes discontinuous and on-time rate falls lower than 30%, the PFM circuit operates to output a pulse with 30% of a fixed on-time

rate from the Lx pin. During PFM operation with this fixed on-time rate, pulses are generated at different frequencies according to conditions of

the moment. This causes a reduction in the number of switching operations per unit of time, resulting in efficiency improvement under light load

conditions. However, since pulse output frequency is not constant, consideration should be given if a noise filter or the like is needed.

Necessary conditions for switching to PFM operation depend on input voltage, load current, coil value and other factors.

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁOPERATIONAL EXPLANATION (Continued)

< Synchronous / Non-synchronous >

The XC9509 series automatically switches synchronous / non synchronous according to the state of the DC/DC converter.

In the series, highly efficient operation using the synchronous mode while the coil current is in a continuation state.

The series enters non-synchronous operation when the built-in Nch switching transistor for synchronous operation is shutdown which happens

when the load current becomes low and the operation changes to a discontinuous state.

The IC can operate without an external schottky diode because the parasitic diode in the Nch switching transistor provides the circuit's step-

down operation. However, since Vf of the parasitic diode is high 0.6V, the efficiency level during non-synchronous operation shows a slight

decrease. Please use an external schottky diode if high efficiency is required during light load current.

ꢃ Continuous Mode : Synchronous

ꢃ Discontinuous Mode : Non-Synchronous

ILmax

CoilCurrent

ILmax

0mA

ILmin

0mA

CoilCurrent

Wave Form

WaveForm

< Current Limit >

The current limiter circuit of the XC9509 series monitors the current flowing through the P-channel MOS driver transistor connected to the Lx

pin, and features a combination of the constant-current type current limit mode and the operation suspension mode.

1 When the driver current is greater than a specific level, the constant-current type current limit function operates to turn off the pulses from

the Lx pin at any given timing.

2 When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state.

3 At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over current state.

4 When the over current state is eliminated, the IC resumes its normal operation.

The IC waits for the over current state to end by repeating the steps 1 through 3 . If an over current state continues for 8msec and the above

three steps are repeatedly performed, the IC performs the function of latching the OFF state of the driver transistor, and goes into operation

suspension mode. Once the IC is in suspension mode, operations can be resumed by either turning the IC off via the CE pin, or by restoring

power to the VIN pin. The suspension mode does not mean a complete shutdown, but a state in which pulse output is suspended; therefore,

the internal circuitry remains in operation. The constant-current type current limit of the XC9509 series can be set at 1.2A.

Limit<8mS ^*

Limit>8mS^*

CurrentLimitLEVEL

IDOUT

DCOUT

0mA

VSS

Restart

VIN

*1.2MHz,Typical

Semiconductor Ltd.

Data Sheet

XC9509 Series

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

ꢁOPERATIONAL EXPLANATION (Continued)

< U.V.L.O. Circuit>

When the VIN pin voltage becomes 1.4 V or lower, the P-channel output driver transistor is forced OFF to prevent false pulse output caused by

unstable operation of the internal circuitry. When the VIN pin voltage becomes 1.8 V or higher, switching operation takes place. By releasing

the U.V.L.O. function, the IC performs the soft start function to initiate output startup operation. The soft start function operates even when the

VIN pin voltage falls momentarily below the U.V.L.O. operating voltage. The U.V.L.O. circuit does not cause a complete shutdown of the IC, but

causes pulse output to be suspended; therefore, the internal circuitry remains in operation.

ꢃHigh Speed LDO Voltage Regulator

The voltage regulator block of the XC9509 series consists of a reference voltage source, error amplifier, and current limiter circuit.

The voltage divided by split resistors is compared with the internal reference voltage by the error amplifier. The P-Channel MOSFET, which is

connected to the VROUT pin, is then driven by the subsequent output signal. The output voltage at the VROUT pin is controlled and stabilized

by a system of negative feedback. A stable output voltage is achievable even if used with low ESR capacitors as a phase compensation circuit

is built-in.

< Reference Voltage Source >

The reference voltage source provides the reference voltage to ensure stable output voltage of the regulator.

< Error Amplifier >

The error amplifier compares the reference voltage with the signal from VROUT, and the amplifier controls the output of the Pch driver transistor.

The voltage regulator block includes a combination of a constant current limiter circuit and a foldback circuit. The voltage regulator senses

output current of the built-in P channel output driver transistor inside. When the load current reaches the current limit level, the current limiter

circuit operates and the output voltage of the voltage regulator block drops. As a result of this drop in output voltage, the foldback circuit

operates, output voltage drops further and the load current decreases. When the VROUT and GND pin are shorted, the load current of about

30mA flows.

ꢃVoltage Detector

The detector block of the XC9509 series detects output voltage from the VDOUT pin while sensing either VDD, DCOUT, or VROUT internally.

(N channel Open Drain Type)

The operation of the XC9509 series' DC/DC converter block and voltage regulator block will enter into the shut down mode when a low level

signal is input to the CE pin. During the shut down mode, the current consumption occurs only in the detector and is 0.6 µA (TYP.), with a state

of high impedance at the Lx pin and the DCOUT pin. The IC starts its operation by inputting a high level signal to the CE pin. The input to the

CE pin is a CMOS input and the sink current is 0 µA (TYP.).

The operation of the XC9509A series' voltage detector block will enter into stand-by mode when a high level signal is input to the MODE pin.

When a low level signal is input, the voltage regulator block will enter into stand-by mode. However, if the IC enters into stand-by mode via the

CE pin, the voltage regulator block also shuts down. Likewise, if the XC9509B series enters into stand-by mode via the CE pin, the DC/DC

converter block can also shut down. With the XC9509C series control can be PWM control when the MODE pin is 'H' level and PWM/PFM

automatic switching control when the MODE pin is 'L' level.

Semiconductor Ltd.

Data Sheet

XC9509A [TOREX]

相关型号：

XC9509A033AL

XC9509A033AR

XC9509A033DL

XC9509A033DR

XC9509A036AL

XC9509A036AR

XC9509A036DL

XC9509A036DR

XC9509A03CAL

XC9509A03CAR

XC9509A03CDL

XC9509A03CDR