参数资料
型号: TPS54110PWP
厂商: TEXAS INSTRUMENTS INC
元件分类: 稳压器
英文描述: 3.5 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO20
封装: GREEN, PLASTIC, HTSSOP-20
文件页数: 11/30页
文件大小: 870K
代理商: TPS54110PWP
d
(SS)
1.2V
t =C
5 a
m
(SS)
0.7V
t
=C
5 a
m
SLVS500C
– DECEMBER 2003 – REVISED FEBRUARY 2011
DETAILED DESCRIPTION
Under Voltage Lock Out (UVLO)
The TPS54110 incorporates an under voltage lockout circuit to keep the device disabled when the input voltage
(VIN) is insufficient. During power up, internal circuits are held inactive until VIN exceeds the nominal UVLO
threshold voltage of 2.95 V. Once the UVLO start threshold is reached, device start-up begins. The device
operates until VIN falls below the nominal UVLO stop threshold of 2.8 V. Hysteresis in the UVLO comparator,
and a 2.5-
s rising and falling edge deglitch circuit reduce the likelihood of shutting the device down due to noise
on VIN.
Slow-Start/Enable (SS/ENA)
The slow-start/enable pin provides two functions; first, the pin acts as an enable (shutdown) control by keeping
the device turned off until the voltage exceeds the start threshold voltage of approximately 1.2 V. When SS/ENA
exceeds the enable threshold, device start up begins. The reference voltage fed to the error amplifier is linearly
ramped up from 0 V to 0.891 V in 3.35 ms. Similarly, the converter output voltage reaches regulation in
approximately 3.35 ms. Voltage hysteresis and a 2.5-
s falling edge deglitch circuit reduce the likelihood of
triggering the enable due to noise.
The second function of the SS/ENA pin provides an external means of extending the slow-start time with a
low-value capacitor connected between SS/ENA and AGND. Adding a capacitor to the SS/ENA pin has two
effects on start-up. First, a delay occurs between release of the SS/ENA pin and start up of the output. The delay
is proportional to the slow-start capacitor value and lasts until the SS/ENA pin reaches the enable threshold. The
start-up delay is approximately:
(25)
Second, as the output becomes active, a brief ramp-up at the internal slow-start rate may be observed before the
externally set slow-start rate takes control and the output rises at a rate proportional to the slow-start capacitor.
The slow-start time set by the capacitor is approximately:
(26)
The actual slow-start is likely to be less than the above approximation due to the brief ramp-up at the internal
rate.
VBIAS Regulator (VBIAS)
The VBIAS regulator provides internal analog and digital blocks with a stable supply voltage over variations in
junction temperature and input voltage. A high quality, low-ESR, ceramic bypass capacitor is required on the
VBIAS pin. X7R or X5R grade dielectrics are recommended because their values are more stable over
temperature. Place the bypass capacitor close to the VBIAS pin and returned to AGND. External loading on
VBIAS is allowed, with the caution that internal circuits require a minimum VBIAS of 2.70 V, and external loads
on VBIAS with ac or digital switching noise may degrade performance. The VBIAS pin may be useful as a
reference voltage for external circuits.
Voltage Reference
The voltage reference system produces a precise Vref signal by scaling the output of a temperature stable
bandgap circuit. During manufacture, the bandgap and scaling circuits are trimmed to produce 0.891 V at the
output of the error amplifier, with the amplifier connected as a voltage follower. The trim procedure adds to the
high precision regulation of the TPS54110, since it cancels offset errors in the scale and error amplifier circuits.
Oscillator and PWM Ramp
The oscillator frequency can be set to internally fixed values of 350 kHz or 550 kHz using the SYNC pin as a
static digital input. If a different frequency of operation is required for the application, the oscillator frequency can
be externally adjusted from 280 kHz to 700 kHz by connecting a resistor from the RT pin to ground and floating
the SYNC pin. The switching frequency is approximated by the following equation, where R is the resistance
from RT to AGND:
2003–2011, Texas Instruments Incorporated
19
Product Folder Link(s): TPS54110
相关PDF资料
PDF描述
TPS54110PWPG4 3.5 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO20
TPS54140QDRCRQ1 SWITCHING REGULATOR, PDSO10
TPS54160DRCT SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO10
TPS54160DGQ 2.7 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO10
TPS54160DGQR 2.7 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO10
相关代理商/技术参数
参数描述
TPS54110PWPG4 功能描述:直流/直流开关调节器 1.5A Step Down Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
TPS54110PWPR 功能描述:直流/直流开关调节器 1.5A Step Down Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
TPS54110PWPRG4 功能描述:直流/直流开关调节器 1.5A Step Down Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
TPS54110-Q1 制造商:TI 制造商全称:Texas Instruments 功能描述:3-V TO 6-V INPUT, 1.5-A OUTPUT SYNCHRONOUS-BUCK PWM SWITCHER WITH INTEGRATED FETs (SWIFT?£a)
TPS54110QPWPRQ1 功能描述:直流/直流开关调节器 3-6V Input 1.5A Out Synch Buck PWM Swer RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5