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参数资料
| 型号： | TPS650240RHBT |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 电源管理 |
| 英文描述： | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC32 |
| 封装： | 5 X 5 MM, GREEN, PLASTIC, QFN-32 |
| 文件页数： | 11/35页 |
| 文件大小： | 955K |
| 代理商： | TPS650240RHBT |
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SOFT START
100% DUTY CYCLE LOW DROPOUT OPERATION
Vin
min + Voutmin ) Ioutmax
RDSonmax ) RL
(3)
LOW DROPOUT VOLTAGE REGULATORS
UNDERVOLTAGE LOCKOUT
POWER-UP SEQUENCING
www.ti.com .............................................................................................................................................................. SLVS774B – JUNE 2007 – REVISED JULY 2009
Each of the three converters has an internal soft start circuit that limits the inrush current during start-up. The soft
start is realized by using a very low current to initially charge the internal compensation capacitor. The soft start
time is typically 750
s if the output voltage ramps from 5% to 95% of the final target value. If the output is
already pre-charged to some voltage when the converter is enabled, then this time is reduced proportionally.
There is a short delay of typically 170
s between the converter being enabled and switching activity actually
starting. This is to allow the converter to bias itself properly, to recognize if the output is pre-charged, and if so, to
prevent discharging of the output while the internal soft start ramp catches up with the output voltage.
The TPS65024x converters offer a low input to output voltage difference while still maintaining operation with the
use of the 100% duty cycle mode. In this mode the P-channel switch is constantly turned on. This is particularly
useful in battery-powered applications to achieve the longest operation time by taking full advantage of the whole
battery voltage range. The minimum input voltage required to maintain DC regulation depends on the load
current and output voltage and can be calculated as:
With:
Ioutmax = Maximum load current (note: ripple current in the inductor is zero under these conditions)
RDSonmax = Maximum P-channel switch RDSon
RL = DC resistance of the inductor
Voutmin = Nominal output voltage minus 2% tolerance limit
The low dropout voltage regulators are designed to operate well with low value ceramic input and output
capacitors. They operate with input voltages down to 1.5V. The LDOs offer a maximum dropout voltage of
300mV at the rated output current. Each LDO sports a current limit feature. Both LDOs are enabled by the
EN_LDO pin. The LDOs also have reverse conduction prevention. This allows the possibility to connect external
regulators in parallel in systems with a backup battery. The TPS65024x step-down and LDO voltage regulators
automatically power down when the Vcc voltage drops below the UVLO threshold or when the junction
temperature rises above 160°C.
The undervoltage lockout circuit for the five regulators on the TPS65024x prevents the device from
malfunctioning at low input voltages and from excessive discharge of the battery. It disables the converters and
LDOs. The UVLO circuit monitors the Vcc pin; the threshold is set internally to 2.35V with 5% (120mV)
hysteresis. Note that when any of the DC/DC converters are running there is an input current at the Vcc pin,
which can be up to 3mA when all three converters are running in PWM mode. This current needs to be taken
into consideration if an external RC filter is used at the Vcc pin to remove switching noise from the TPS65024x
internal analog circuitry supply. See the Vcc-Filter section for details on the external RC filter.
The TPS65024x power-up sequencing is designed to be entirely flexible and customer driven; this is achieved
simply by providing separate enable pins for each switch-mode converter and a common enable signal for LDO1
and LDO2. The relevant control pins are described in Table 1.
Table 1. Control Pins for DCDC Converters
INPUT/
PIN NAME
FUNCTION
OUTPUT
DEFDCDC3
I
Defines the default voltage of the VDCDC3 switching converter. See table 4 for details.
DEFDCDC2
I
Defines the default voltage of the VDCDC2 switching converter. DEFDCDC2 = 0 defaults VDCDC2 to 1.8V,
DEFDCDC2 = VCC defaults VDCDC2 to 2.5V.
DEFDCDC1
I
Defines the default voltage of the VDCDC1 switching converter. DEFDCDC1 = 0 defaults VDCDC1 to 2.80V,
DEFDCDC1 = VCC defaults VDCDC1 to 3.3V.
Copyright 2007–2009, Texas Instruments Incorporated
19
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相关代理商/技术参数 |
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| TPS650240RHBTG4 | 功能描述:电池管理 Pwr Mgmt ICs RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| TPS650241EVM-234 | 功能描述:电源管理IC开发工具 TPS650241 Eval Mod RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| TPS650241QRHBRQ1 | 功能描述:电池管理 Aut Cat Pwr Mgmt Ics RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| TPS650241RHBR | 功能描述:电池管理 Pwr Mgmt ICs for Li-Ion Powered Sys RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| TPS650241RHBRG4 | 功能描述:电池管理 Pwr Mgmt ICs for Li-Ion Pwred Sys RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
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