The JTMT201XCL/JTMT201XCL series is a synchronous step-down

时间:2016-03-12 18:00来源:未知 作者:oumao18 点击:
目录 1. 产品概述 2. 产品特点 3. 应用范围 4. 技术规格书下载(产品PDF文档 ) 5. 产品封装图 6. 电路原理图 7. 功能概述 8 . 相关产品 一 , 产品概述( General Description) The JTMT201XCL/JTMT201XCL series is
目录

,产品概述(General Description)      
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   The JTMT201XCL/JTMT201XCL series is a synchronous step-down micro DC/DC converter which
integrates an inductor and 
 a control IC in one tiny package (2.5mm×2.0mm, h=1.0mm). A stable power
supply with an output current of 400mA is 
configured using only two capacitors connected externally.
Operating voltage range is from 2.0V to 6.0V.
    Output voltage is internally set in a range from 0.8V to 4.0V in increments of 0.05V. The device is operated
by 1.2MHz, and includes 0.42ΩP-channel driver transistor and 0.52ΩN-channel switching 
transistor. As for
operation mode, the JTMT201XCL series is PWM control, the JTMT202XCL series is automatic PWM/PFM
switching 
control, allowing fast response, low ripple and high efficiency over the full range of loads (from light
load to heavy load).
During stand-by, the device is shutdown to reduce current consumption to as low as 1.0μA
or less. With the built-in UVLO 
(Under Voltage Lock Out) function, the internal driver transistor is forced OFF
when input voltage becomes 1.4V or lower.
The series provide short-time turn-on by the soft start function
internally set in 0.25ms (TYP). The series integrate CL auto 
discharge function which enables the electric
charge stored at the output capacitor CL to be discharged via the internal auto-
discharge switch located
between the LX and VSS pins. When the devices enter stand-by mode, output voltage quickly returns
to the VSS level as a result of this function
.产品特点(Features)
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Ultra Small            : 2.5mm×2.0mm, h=1.0mm
Input Voltage           : 2.0V ~ 6.0V
Output Voltage          : 0.8V ~ 4.0V (±2.0%)
High Efficiency          : 92%(VIN=4.2V,VOUT=3.3V)
Output Current          : 400mA
Oscillation Frequency     : 1.2MHz (±15%)
Maximum Duty Cycle     : 100%
Output Capacitor        : Low ESR Ceramic
Function              : Current Limiter Circuit
  (Constant Current & Latching)
  Soft-Start Circuit Built-In
  CL Discharge
Control Methods         : PWM (JTMT201)
  PWM/PFM Auto (JTMT202)
Operating Ambient Temperature : -40℃~+85℃
Environmentally Friendly   : EU RoHS Compliant, Pb Free

,应用范围 (Applications)
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●Mobile phones, Smart phones
●Bluetooth Headsets
●WiMAX PDAs, MIDs, UMPCs
●Portable game consoles
●Digital cameras, Camcorders
●SSD(Solid State Drive)
●PND(Portable Navigation Device)
四.技术规格书下载(产品PDF)
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JTMT201XCL/JTMT202XCL
五,产品封装图 (Package)
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    JTMT201XCL/JTMT202XCL PIN CONFIGURATION
Inductor Electrodes
PIN NUMBER PIN NAME FUNCTIONS
1 Lx Switching Output
2,5 VSS Ground
3 VOUT Output Voltage
4 CE Chip Enable
6 VIN Power Input
7 L1 Inductor Electrodes
8 L2
六.电路原理图
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   JTMT201XCL/JTMT202XCL TYPICAL APPLICATION CIRCUIT
,功能概述
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The JTMT201XCL/JTMT202XCL series consists of a reference voltage source, ramp wave circuit, error amplifier,
PWM comparator, phase compensation circuit, output voltage adjustment resistors, P-channel MOSFET driver
transistor, N-channel MOSFET switching transistor for the synchronous switch, current limiter circuit, UVLO circuit
with control IC, and an inductor. (See the block diagram below.) Using the error amplifier, the voltage of the internal
voltage reference source is compared with the feedback voltage from the VOUT pin through split resistors, R1 and R2.
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
八,相关芯片选择指南
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系列名称 特点 输入电压 输出电压 最大输出电流 振荡频率 内置FET 封装
(V) (V) (mA)
最小 最大 最小 最大  
JTMT101XCL Inductor Built-in Step-up 0.9 5.5 1.8 5 100 1.2MHz P-ch FET CL-2025
N-ch FET CL2025-02
JTMT201XCL Inductor Built-in 2 6 0.8 4 400 1.2MHz N-ch FET CL-2025
JTMT202XCL P-ch FET CL2025-02
JTMT205XCL Inductor Built-in 2 6 0.8 4 600 3.0MHz N-ch FET CL-2025
JTMT206XCL P-ch FET CL2025-02
JTMT207XCL    
JTMT208XCL Inductor Built-in 1.8 6 0.8 4 400 3.0MHz N-ch FET USP-10B03
JTMT209XCL P-ch FET
JTMT210XCL Inductor Built-in 2 6 1 4 - - Pch CL2025-02
Nch
JTMT211XCL Inductor Built-in 2.7 6 0.9~VIN 2000 2.4MHz N-ch FET USP-11B01
JTMT212XCL P-ch FET
JTMT213XCL Inductor Built-in 2.7 5.5 0.8 3.6 1500 3.0MHz N-ch FET USP-9B01
JTMT214XCL P-ch FET
JTMT219XCL Inductor Built-in 2.5 5.5 0.8 3.6 1000 3.0MHz N-ch FET CL2025-02
JTMT220XCL P-ch FET
   
JTMT221XCL Inductor Built-in 2.5 5.5 0.8 3.6 500 1.2MHz N-ch FET CL2025-02
JTMT222XCL P-ch FET
   

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