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参数资料
| 型号： | MAX1798AEUP |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 基准电压源/电流源 |
| 英文描述： | CDMA Cellular/PCS System Power Supplies |
| 中文描述： | FIVE OUTPUT, ADJUSTABLE POSITIVE LDO REGULATOR, PDSO20 |
| 封装： | 4.40 MM, MO-153, TSSOP-20 |
| 文件页数： | 11/20页 |
| 文件大小： | 642K |
| 代理商： | MAX1798AEUP |
M
CDMA Cellular/PCS System
Power Supplies
______________________________________________________________________________________
11
Detailed Description
The MAX1798/MAX1798A/MAX1799/MAX1799A drive
CDMA cellular and PCS handsets or systems with
inputs from 2.5V to 5.5V. The devices contain five
LDOs, two open-drain outputs, and a reset output as
shown in Figure 1. All outputs are individually program-
mable through either an SPI (MAX1798/MAX1798A) or
I
2
C (MAX1799/MAX1799A) serial-port interface. The
outputs may be turned on or off individually through the
serial interface. Their output voltages are adjustable
from 1.8V to 3.3V in 32 increments. At power-up, all
outputs are at a default value of 2.98V, but only OUT1
is on. OUT1 is rated for 300mA and optimized for low
dropout. OUT2
–
5 are rated for 150mA. All LDOs are
optimized for low noise, high isolation, and low dropout.
Linear Regulator 1
Regulator 1 is a low-dropout linear regulator that
sources 300mA (max), operating from a 2.5V to 5.5V
input voltage (V
IN1
). OUT1 is turned on by using the on
button. OUT1 is turned off by using either the off pin or
the serial port. Its output can be adjusted from 1.8V to
3.3V from the SPI or I
2
C serial-port interface by setting
the control data byte (Table 1). OUT1 is always on
when the MAX1798/MAX1798A/MAX1799/MAX1799A
are on. If OUT1 is turned off, the entire IC shuts down. If
V
IN1
falls below 1V, a POR circuit resets all LDO volt-
ages to 2.98V and OUT1 is left on while OUT2
–
5 are
turned off.
Linear Regulators 2–5
Regulators 2
–
5 are LDOs that source 150mA (max)
from input voltages (V
IN2/3
and V
IN4/5
) of 2.5V to 5.5V.
OUT2
–
5 can be turned on or off and adjusted from 1.8V
to 3.3V through the SPI or I
2
C serial-port interface by
setting the control data byte (Table 1). At power-up,
OUT2
–
5 are set to 2.98V, but turned off. The control
data byte must be used to turn them on. If V
IN1
falls
below 1V, a POR circuit resets all LDO voltages to
2.98V and OUT2
–
5 are turned off. If V
IN2/3
or V
IN4/5
fall
below 2.15V, the UVLO circuit turns off the correspond-
ing output, but all LDO voltages remain at their prior
settings. OUT2
–
5 are optimized for low noise and high
isolation.
Open-Drain Outputs
The open-drain N-channel MOSFETs (DR1 and DR2,
Figure 2) have a nominal 2
on-resistance and can be
used to drive up to 10 LEDs for backlight or a vibrator
motor. DR1 and DR2 can sink 100mA
RMS
(max). At
power-up, DR1 and DR2 are high impedance and are
commanded on by the control data byte.
RSO
RSO
is an open-drain output, connected to OUT1
through an internal 14k
resistor. At power-up, OUT1
turns on and
RSO
is held low for 140ms (min). When
RSO
goes high,
OFF
must be brought high within 35ms to
keep OUT1 on. Otherwise, if
OFF
is low, the watchdog
timer circuit counts down 35ms (min), and
RSO
is
actively held low while the entire device turns off.
The MAX1798/MAX1799
RSO
goes low when OUT1
droops by more than 7.5% ±2% of its programmed out-
put voltage. The MAX1798A/MAX1799A
RSO
goes low
when OUT1 droops by more than 13% ±2% of its pro-
grammed output voltage.
RSO
stays low for 140ms
(min) after OUT1 rises above the threshold. During this
time, the watchdog timer circuit is inactive.
The MAX1798A/MAX1799A have an additional timer
circuit to shut down the regulators when the
RSO
and
watchdog timer time out. If the OUT1 voltage level ever
exceeds the
RSO
threshold level before the reset and
OUT2 DAC
OUT3 DAC
OUT4 DAC
OUT5 DAC
Driver Outputs
ON/OFF Conrol
C1
0
1
1
0
0
1
1
C2
0
FUNCTION
0
0
0
1
1
1
1
OUT1 DAC
0
Update DAC Outputs
COMMAND
C0
1
0
1
0
1
0
1
0
D4
U5
X
D2
D3
U3
U4
X
D1
X
DR2
ON2
DIN (SDA)
D0
U1
DR1
ON1
Table 1. Control Data Byte
Note:
C2 is MSB, and D0 is LSB. X = Don’t care.
U2
DAC1 (Table 2)
DAC1 (Table 2)
DAC1 (Table 2)
DAC1 (Table 2)
DAC1 (Table 2)
ON5
ON3
ON4
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1799EGP | CDMA Cellular/PCS System Power Supplies |
| MAX1798EGP | Replaced by TMS320C6722B : Digital Signal Processor 144-QFP |
| MAX1798EUP | Replaced by TMS320C6722B : Digital Signal Processor 144-QFP |
| MAX1799AEUP | Replaced by TMS320C6727B : Digital Signal Processors 325-CPGA 0 to 70 |
| MAX1799EUP | Replaced by TMS320C6727B : Digital Signal Processors 325-CPGA |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1798AEUP-T | 功能描述:PMIC 解决方案 CDMA Cellular/PCS System Power Supply RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
| MAX1798EGP | 功能描述:PMIC 解决方案 RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
| MAX1798EGP+ | 功能描述:PMIC 解决方案 CDMA Cellular/PCS System Power Supply RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
| MAX1798EGP+T | 功能描述:PMIC 解决方案 CDMA Cellular/PCS System Power Supply RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
| MAX1798EGP-T | 功能描述:PMIC 解决方案 RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
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