|
|
PDF MAX8621Y Data sheet ( Hoja de datos )
| Número de pieza | MAX8621Y | |
| Descripción | Dual Step-Down DC-DC Power-Management ICs | |
| Fabricantes | Maxim Integrated Products | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MAX8621Y (archivo pdf) en la parte inferior de esta página. Total 18 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
19-3539; Rev 1; 8/05
EVAALVUAAILTAIOBNLEKIT
Dual Step-Down DC-DC Power-Management ICs
for Portable Devices
General Description
The MAX8621Y/MAX8621Z power-management inte-
grated circuits (PMICs) are designed for a variety of
portable devices including cellular handsets. These
PMICs include two high-efficiency step-down DC-DC
converters, four low-dropout linear regulators (LDOs)
with pin-programmable capability, one open-drain dri-
ver, a 60ms (typ) reset timer, and power-on/off control
logic. These devices offer high efficiency with a no-load
supply current of 160µA, and their small thin QFN 4mm
x 4mm package makes them ideal for portable devices.
The step-down DC-DC converters utilize a proprietary
4MHz hysteretic-PWM control scheme that allows for
ultra-small external components. Internal synchronous
rectification improves efficiency and eliminates the
external Schottky diode that is required in conventional
step-down converters. The output voltage is adjustable
from 0.6V to 3.3V. The output current is guaranteed up
to 500mA.
The four LDOs offer low 45µVRMS output noise and low
dropout of only 100mV at 100mA. OUT1 and OUT2
deliver 300mA (min) of continuous output current.
OUT3 and OUT4 deliver 150mA (min) of continuous
output current. The output voltages are pin selectable
by SEL1 and SEL2 for flexibility. The MAX8621Y/
MAX8621Z offer different sets of LDO output voltages.
A microprocessor reset output (RESET) monitors OUT1
and warns the system of impending power loss, allow-
ing safe shutdown. RESET asserts during power-up,
power-down, shutdown, and fault conditions where
VOUT1 is below its regulation voltage.
A 200mA driver output is provided to control LED back-
lighting or provide an open-drain connection for resis-
tors such as in feedback networks.
Applications
Cellular Handsets
Smart Phones, PDAs
Digital Cameras
MP3 Players
Wireless LAN
Pin Configuration appears at end of data sheet.
Features
♦ Two 500mA Step-Down Converters
Up to 4MHz Switching Frequency
Adjustable Output from 0.6V to 3.3V
♦ Four Low-Noise LDOs with Pin-Programmable
Output Voltages
♦ One Open-Drain Driver
♦ 60ms (typ) Reset Timer
♦ Power-On/Off Control Logic and Sequencing
♦ 4mm x 4mm x 0.8mm 24-Pin Thin QFN
Ordering Information
PART
MAX8621YETG
TEMP RANGE
-40°C to +85°C
MAX8621YETG+ -40°C to +85°C
MAX8621ZETG -40°C to +85°C
MAX8621ZETG+ -40°C to +85°C
+ Denotes lead-free package.
PIN-PACKAGE
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
24 Thin QFN
4mm x 4mm (T2444-4)
Typical Operating Circuit
INPUT
2.6V TO 5.5V
LX1
IN1
MAX8621Y FB1
MAX8621Z
IN2
BUCK1
1.375V, 500mA
IN3
PWRON
SEL1
SEL2
EN2
EN3
EN4
ENDR
REFBP
PGND1
LX2
FB2
PGND2
OUT1
RESET
OUT2
OUT3
OUT4
GND DR
BUCK2
1.8V, 500mA
OUT1
2.6V, 300mA
RESET
OUT2
2.6V, 300mA
OUT3
1.8V, 150mA
OUT4
3V, 150mA
INPUT
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1 page  
Dual Step-Down DC-DC Power-Management ICs
for Portable Devices
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 3.7V, CIN1 = 10µF, CIN2 = CIN3 = 4.7µF, COUT1 = COUT2 = 4.7µF, COUT3 = COUT4 = 2.2µF, CREFBP = 0.01µF, TA = -40°C to
+85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2)
PARAMETER
CONDITIONS
MIN TYP MAX UNIT
Power-Supply Rejection
ΔVOUT3/ΔVIN2
Output Noise Voltage (RMS)
Output Capacitor for Stable
Operation
10Hz to 10kHz, COUT3 = 2.2µF, ILOAD = 30mA
100Hz to 100kHz, COUT3 = 2.2µF, ILOAD = 30mA
0 < ILOAD < 150mA
60 dB
45 µVRMS
2.2 µF
OUT4 (LDO4)
Output Voltage Accuracy
Output Current
Current Limit
Dropout Voltage
Load Regulation
Power-Supply Rejection
ΔVOUT4/ΔVIN2
Output Noise Voltage (RMS)
Output Capacitor for Stable
Operation
DRIVER (DR)
ENDR Turn-On Threshold
ENDR Input Current
DR Output Low Voltage
DR Off-Current (Leakage)
RESET
ILOAD = 1mA, 3.7V ≤
VIN_ ≤ 5.5V, relative to
VOUT(NOM)
TA = 0°C to VOUT(NOM) ≥ 1.8V
+85°C
VOUT(NOM) = 1.5V
TA = -40°C to +85°C
ILOAD = 75mA, relative to VOUT(NOM)
-1.3
-1.30
-2.3
VOUT4 = 0V
ILOAD = 100mA, TA = +85°C
1mA < ILOAD < 150mA, VSEL1 = VSEL2 = 0
10Hz to 10kHz, COUT4 = 2.2µF, ILOAD = 30mA
100Hz to 100kHz, COUT4 = 2.2µF, ILOAD = 30mA
0 < ILOAD < 150mA
165
+0.3
+0.3
0
360
100
0.6
60
45
2.2
+2.0
+2.35
+2.5
%
150 mA
650 mA
210 mV
%
dB
µVRMS
µF
IDR = 1mA
VENDR = 0V and 5.5V
IDR = 150mA, VENDR = 3.7V
VDR = VIN = 5.5V, VENDR = 0V
0.65
-1 +1
0.2 0.4
-1 +1
V
µA
V
µA
Output High Voltage
VOUT1
- 0.3V
V
Output Low Voltage
RESET Threshold
RESET Active Timeout Period
ISINK = 1mA
Percentage of nominal OUT1 rising when RESET falls
From OUT1 ≥ 87% until RESET = HIGH
0.3 V
84 87 90
%
60 ms
Pullup Resistance to OUT1
8 14 20 kΩ
Note 1: VIN1, VIN2, and VIN3 are shorted together and single input is referred to as VIN.
Note 2: All units are 100% production tested at TA = +85°C. Limits over the operating range are guaranteed by design.
Note 3: OUT1, OUT2, OUT3, OUT4, LX1, and LX2 to ground.
Note 4: When the input voltage is greater than 2.85V (typ), the UVLO comparator trips and the threshold is reduced to 2.35V (typ).
This allows the system to start normally until the input voltage decays to 2.35V.
_______________________________________________________________________________________ 5
5 Page 
Dual Step-Down DC-DC Power-Management ICs
for Portable Devices
Table 1. SEL1 and SEL2, MAX8621Y/MAX8621Z Output Voltage Selection
SEL1
IN
IN
IN
OPEN
OPEN
OPEN
GND
GND
GND
SEL2
IN
OPEN
GND
IN
OPEN
GND
IN
OPEN
GND
OUT1 (V)
3.3
3.0
2.5
2.85
3.3
3.3
3.3
2.85
3.3
MAX8621Y
OUT2 (V) OUT3 (V)
3.3 2.85
3.3 3.3
3.3 2.85
3.3 3.0
3.3 2.8
3.3 3.0
2.85 3.3
2.85 3.3
2.85 3.0
OUT4 (V)
2.85
2.85
3.0
2.5
3.0
3.0
2.85
3.3
3.0
OUT1 (V)
2.8
2.6
2.6
2.6
2.6
2.6
2.9
3.0
3.0
MAX8621Z
OUT2 (V) OUT3 (V)
2.6 3.0
2.6 3.0
2.6 2.9
2.6 3.0
2.6 1.8
2.6 2.8
3.1 1.8
2.9 2.9
2.5 2.9
OUT4 (V)
3.0
3.0
2.9
3.3
3.0
3.0
1.5
2.9
2.9
Power-Supply Sequence
BUCK1 is always first on and last off in the MAX8621Y/
MAX8621Zs’ power sequence. BUCK1 turns on approxi-
mately 40µs after PWRON is enabled. BUCK2 turns on
approximately 40µs after BUCK1, and OUT1 turns on
65µs after BUCK2. These delays have been added to
sequence the turn-on of the step-down converters and
LDOs so that the initial current surges are distributed
over time. For the same reason, OUT2, OUT3, and OUT4
can be turned on by EN2, EN3, and EN4 signals, but
only after OUT1 has reached 87% of its final value. Note
that OUT2 typically requires a longer time to enable than
OUT3 and OUT4 (45µs versus 15µs). All regulators can
be turned off at the same time when PWRON is low, but
BUCK1 remains on for approximately another 120µs
after PWRON goes low.
PWRON
REF
BUCK1
BUCK2
OUT1
RESET
OUT2
EN3
(EN4)
OUT3
(OUT4)
40μs
40μs
65μs
87% REGULATION
60ms
45μs
15μs
EN2
120μs
87% REGULATION
Figure 2. Power-On/Off Sequence Diagram
______________________________________________________________________________________ 11
11 Page | ||
| Páginas | Total 18 Páginas | |
| PDF Descargar | [ Datasheet MAX8621Y.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MAX8621Y | Dual Step-Down DC-DC Power-Management ICs | Maxim Integrated Products |
| MAX8621Z | Dual Step-Down DC-DC Power-Management ICs | Maxim Integrated Products |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |