参数资料
型号: TPS54623RHLT
厂商: TEXAS INSTRUMENTS INC
元件分类: 稳压器
英文描述: 15 A SWITCHING REGULATOR, 1760 kHz SWITCHING FREQ-MAX, PQCC14
封装: 3.50 X 3.50 MM, GREEN, PLASTIC, QFN-14
文件页数: 2/35页
文件大小: 1468K
代理商: TPS54623RHLT
SLVSB09
– SEPTEMBER 2011
TYPICAL CHARACTERISTICS (continued)
The device reduces the external component count by integrating the boot recharge circuit. The bias voltage for
the integrated high-side MOSFET is supplied by a capacitor between the BOOT and PH pins. The boot capacitor
voltage is monitored by a BOOT to PH UVLO (BOOT-PH UVLO) circuit allowing PH pin to be pulled low to
recharge the boot capacitor. The device can operate at 100% duty cycle as long as the boot capacitor voltage is
higher than the preset BOOT-PH UVLO threshold which is typically 2.1V. The output voltage can be stepped
down to as low as the 0.6V voltage reference (Vref).
The device has a power good comparator (PWRGD) with hysteresis which monitors the output voltage through
the VSENSE pin. The PWRGD pin is an open drain MOSFET which is pulled low when the VSENSE pin voltage
is less than 92% or greater than 106% of the reference voltage Vref and asserts high when the VSENSE pin
voltage is 94% to 104% of the Vref.
The SS/TR (slow start/tracking) pin is used to minimize inrush currents or provide power supply sequencing
during power up. A small value capacitor or resistor divider should be coupled to the pin for slow start or critical
power supply sequencing requirements.
The device is protected from output overvoltage, overload and thermal fault conditions. The device minimizes
excessive output overvoltage transients by taking advantage of the overvoltage circuit power good comparator.
When the overvoltage comparator is activated, the high-side MOSFET is turned off and prevented from turning
on until the VSENSE pin voltage is lower than 104% of the Vref. The device implements both high-side MOSFET
overload protection and bidirectional low-side MOSFET overload protections which help control the inductor
current and avoid current runaway. The device also shuts down if the junction temperature is higher than thermal
shutdown trip point. The device is restarted under control of the slow start circuit automatically after the built-in
thermal shutdown hiccup time.
The TPS54623 monitors the peak switch current of the high-side MOSFET. Once the peak switch current is
lower than typically 1A, the device stops switching to boost the efficiency until the peak switch current is higher
than typically 1A again.
DETAILED DESCRIPTION
Fixed Frequency PWM Control
The device uses a adjustable fixed frequency, peak current mode control. The output voltage is compared
through external resistors on the VSENSE pin to an internal voltage reference by an error amplifier which drives
the COMP pin. An internal oscillator initiates the turn on of the high-side power switch. The error amplifier output
is converted into a current reference which compares to the high-side power switch current. When the power
switch current reaches current reference generated by the COMP voltage level the high-side power switch is
turned off and the low-side power switch is turned on.
Continuous Current Mode Operation (CCM)
As a synchronous buck converter, the device normally works in CCM (Continuous Conduction Mode) under load
conditions where the minimum inductor valley current is higher than 0A.
Light Load Efficiency Operation
The TPS54623 operates in pulse skip mode (Figure 18) at light load currents to improve efficiency by reducing
switching and gate drive losses. The TPS54623 is designed so that if the output voltage is within regulation and
the peak switch current at the end of any switching cycle is below the pulse skipping current threshold, the
device enters pulse skip mode.This current threshold is the current level corresponding to a nominal COMP
voltage of 250mV.
When in pulse skip mode, the COMP pin voltage is clamped and the high side MOSFET is inhibited. Further
decreases in load current or in output voltage can not drive the COMP pin below this clamp voltage level.
Since the device is not switching, the output voltage begins to decay. As the voltage control loop compensates
for the falling output voltage, the COMP pin voltage begins to rise. At this time, the high side MOSFET is enabled
and a switching pulse initiates on the next switching cycle. The peak current is set by the COMP pin voltage. The
output voltage re-charges the regulated value, then the peak switch current starts to decrease, and eventually
falls below the pulse skip mode threshold at which time the device again enters pulse skip mode.
10
Copyright
2011, Texas Instruments Incorporated
Product Folder Link(s) :TPS54623
相关PDF资料
PDF描述
TPS54672PWPG4 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28
TPS54810PWPRG4 12 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO28
TPS54810PWPG4 12 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO28
TPS54873PWPG4 12 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO28
TPS54880PWPR 12 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO28
相关代理商/技术参数
参数描述
TPS54625EVM-608 制造商:Texas Instruments 功能描述:TPS54625EVM-608 - Boxed Product (Development Kits) 制造商:Texas Instruments 功能描述:TPS54625 EVAL MOD
TPS54625PWP 制造商:Texas Instruments 功能描述: 制造商:Texas Instruments 功能描述:IC REG BUCK ADJ 6.5A 14HTSSOP 制造商:Texas Instruments 功能描述:IC SYNC STEP DOWN 650KHZ HT
TPS54625PWPR 功能描述:Buck Switching Regulator IC Positive Adjustable 0.765V 1 Output 6.5A 14-TSSOP (0.173", 4.40mm Width) Exposed Pad 制造商:texas instruments 系列:D-CAP2?? 包装:剪切带(CT) 零件状态:有效 功能:降压 输出配置:正 拓扑:降压 输出类型:可调式 输出数:1 电压 - 输入(最小值):4.5V 电压 - 输入(最大值):18V 电压 - 输出(最小值/固定):0.765V 电压 - 输出(最大值):5.5V 电流 - 输出:6.5A 频率 - 开关:650kHz 同步整流器:是 工作温度:-40°C ~ 85°C(TA) 安装类型:表面贴装 封装/外壳:14-TSSOP(0.173",4.40mm 宽)裸焊盘 供应商器件封装:14-HTSSOP 标准包装:1
TPS54626EVM-608 制造商:Texas Instruments 功能描述:TPS54626EVM-608 - Boxed Product (Development Kits) 制造商:Texas Instruments 功能描述:TPS54626 EVAL MOD
TPS54626PWP 制造商:Texas Instruments 功能描述: 制造商:Texas Instruments 功能描述:IC SYNC STEP DOWN 650KHZ HT 制造商:Texas Instruments 功能描述:18V 6.5A DCAP2 sync converter