|
|
PDF MAX1515 Data sheet ( Hoja de datos )
| Número de pieza | MAX1515 | |
| Descripción | Step-Down/DDR Regulator | |
| Fabricantes | Maxim Integrated Products | |
| Logotipo |  |
|
1. MAX1515  Hay una vista previa y un enlace de descarga de MAX1515 (archivo pdf) en la parte inferior de esta página. Total 24 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
19-3507; Rev 1; 3/06
EVAALVUAAILTAIOBNLEKIT
Low-Voltage, Internal Switch,
Step-Down/DDR Regulator
General Description
The MAX1515 constant-off-time, pulse-width-modulated
(PWM) source/sink step-down DC-DC converter is opti-
mized for use in low-voltage active-termination power
rails or chipset power supplies in notebook and sub-
notebook computers. This device features dual internal
n-channel MOSFET power switches for high efficiency
and reduced component count. External Schottky
diodes are not required. An integrated boost switch
eliminates the need for an external boost diode. The
internal 40mΩ NMOS power switches easily source and
sink continuous load currents up to 3A. The MAX1515
produces an adjustable output from +0.5V to +2.7V
and achieves efficiencies as high as 95%.
The MAX1515 can be configured as a DDR regulator,
producing an output that is exactly half the memory
supply rail. The input of the power stage can be taken
from the memory supply rail itself, resulting in an effi-
cient power supply that returns the energy to the rail
from which it was sourced. The MAX1515 includes a
reference buffer that provides ±5mA of drive current.
The MAX1515 uses a unique current-mode, constant-
off-time, PWM control scheme. A selectable pulse-skip-
ping mode maintains high efficiency during light-load
operation, yet still sources and sinks current on
demand. The MAX1515 can also be operated in fixed-
PWM mode for low output ripple. The programmable
constant-off-time architecture sets switching frequen-
cies up to 1MHz, which allows the user to optimize per-
formance trade-offs between efficiency, output
switching noise, component size, and cost. The
MAX1515 features an adjustable soft-start to limit surge
currents during startup and a low-power shutdown
mode to disconnect the input from the output and
reduce supply current below 1µA. The MAX1515 is
available in a 24-pin thin QFN package with an
exposed backside pad.
Applications
Notebook DDR Memory Termination
Active-Termination Buses
Chipset/Graphics Processor Supplies
Pin Configuration appears at end of data sheet.
Features
♦ Dual 40mΩ Internal n-Channel MOSFETs
♦ Integrated Boost Switch
♦ +1.3V to +3.6V Input Voltage Range
♦ 1% VOUT Accuracy Over Line and Load
♦ 1MHz Maximum Switching Frequency
♦ DDR Termination Regulator (DDR Mode)
Tracking Output Voltage
Source/Sink Pulse Skipping
±5mA Reference Buffer
♦ Output Voltage (Non-DDR Mode)
+2.5V, +1.8V, or +1.5V Pin Selectable
+0.5V to +2.7V Adjustable
♦ 1.1V ±0.75% Reference Output
♦ Adjustable Soft-Start Inrush Current Limiting
♦ < 1µA (typ) Shutdown Supply Current
♦ < 800µA (max) Operating Supply Current
♦ Selectable Pulse-Skipping Operation at Light Loads
♦ Positive and Negative Current Limit
♦ Power-Good Window Comparator
♦ Output Short-Circuit Protection
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG CODE
MAX1515ETG -40°C to +85°C 24 Thin QFN T2444-4
4mm x 4mm
MAX1515ETG+ -40°C to +85°C 24 Thin QFN T2444-4
4mm x 4mm
+Denotes lead-free package.
Minimal Operating Circuit
VBIAS
(3.0V TO 3.6V)
VDDQ
(2.5V OR 1.8V)
VDD BST IN
VCC
MAX1515
COMP
PGOOD
LX
FB
SHDN
PGND
MODE
SKIP
REF
GND
FBSEL0
FBSEL1
REFIN
REFOUT
SS
TOFF
VIN
(1.3V TO 3.6V)
VOUT = VTT
VREFOUT = VTTR
________________________________________________________________ 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  
Low-Voltage, Internal Switch,
Step-Down/DDR Regulator
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, VIN = +3.3V, VCC = VDD = SHDN = MODE = +3.3V, VREFIN = VREF, SKIP = GND, TA = -40°C to +85°C, unless
otherwise noted. Note 5)
PARAMETER
PWM CONTROLLER
Input Voltage Range
Output Adjust Range
SYMBOL
CONDITIONS
VIN
VCC, VDD
VFB -
VREFIN
VOUT ≤ VIN
VIN = +3.3V, ILOAD = 0, MODE = VCC
MIN TYP MAX UNITS
1.3 3.6
V
3.0 3.6
0.5
VCC
V
-5 +5 mV
FBSEL0 = VCC,
FBSEL1 = VCC,
REFIN = REF
2.438
2.562
Feedback Voltage Accuracy
FBSEL0 = VCC,
FBSEL1 = GND, 1.755
VFB
VIN = +3.3V, ILOAD = 0,
MODE = low
REFIN = REF
FBSEL0 = GND,
FBSEL1 = VCC, 1.463
REFIN = REF
1.845
1.538
V
Sink-Mode Detect Threshold
Source-Mode Detect Threshold
nFET On-Resistance
Switching Frequency
Current-Limit Threshold
Pulse-Skipping Current Threshold
Off-Time
Maximum On-Time
SS Source Current
SS Sink Current
FBSEL0 = GND,
FBSEL1 = GND,
REFIN = 0.5V
VFB -
VREFIN
VFB -
VREFIN
RNMOS
fSW
ILIMIT_P
MODE = VCC, VREFIN = +0.5V to +1.5V
MODE = VCC, VREFIN = +0.5V to +1.5V
VCC = VDD = VIN = +3.3V, ILOAD = 0.5A
(Note 2)
VIN = +3.3V, MODE = GND or VCC,
positive or sourcing mode
ISKIP_P
tOFF
tON(MAX)
ISS(SRC)
ISS(SNK)
VIN = +3.3V, MODE = GND or VCC,
positive or sourcing mode
VFB > 0.3 x VTARGET
(Note 4)
RTOFF = 33.2kΩ
RTOFF = 110kΩ
RTOFF = 499kΩ
0.487
+15
-35
3.35
0.4
0.250
0.8
3.8
5
3
100
0.513
+35 mV
-15 mV
0.10 Ω
1 MHz
5.05 A
1.2
0.425
1.2
5.2
7
A
µs
µs
µA
µA
_______________________________________________________________________________________ 5
5 Page 
Low-Voltage, Internal Switch,
Step-Down/DDR Regulator
Pin Description
PIN NAME
FUNCTION
1, 2
PGND
Power Ground. Internal connection to the source of the internal synchronous-rectifier switch. Connect
both PGND pins together.
3 IC Internally Connected Pin. Connect to PGND.
Supply Input for the Low-Side Gate Drive and REFOUT Buffer. Connect to the system supply voltage,
4 VDD +3.0V to +3.6V. Bypass to PGND with a 1µF (min) ceramic capacitor. VDD supplies power to the
drivers and the REFOUT buffer.
5 REFOUT REFIN Buffered Output. REFOUT provides a buffered output voltage of REFIN when MODE = VCC.
Bypass to GND with a 0.47µF ceramic capacitor. REFOUT is disabled when MODE = GND.
6 SS Soft-Start. Connect a capacitor from SS to GND to limit the inrush current during startup.
Power-Good Open-Drain Output. PGOOD is low when the output voltage is more than 10% above or
7 PGOOD below the normal regulation point. PGOOD is high impedance when the output is in regulation.
PGOOD is low in shutdown.
8
TOFF
Off-Time Select Input. Connect a resistor from TOFF to GND to adjust the off-time.
Feedback Input.
9 FB In DDR mode (MODE = VCC), FB regulates to the voltage at REFIN.
In non-DDR mode (MODE = GND), connect directly to the output for preset voltage operation or to a
resistive voltage-divider for adjustable-mode operation.
10
COMP
Integrator Compensation. Connect a 470pF capacitor from COMP to VCC for integrator
compensation.
11
VCC
Analog Supply Input. Connect to the system supply voltage, +3.0V to +3.6V, with a series 10Ω
resistor. Bypass to GND with a 1µF (min) ceramic capacitor.
12
GND
Analog Ground. Connect exposed backside pad to GND.
13
REF
+1.1V Reference Voltage Output. Bypass to GND with a 1.0µF bypass capacitor. Can supply 50µA
for external loads. Reference turns off in shutdown.
14
REFIN
External Reference Input. In DDR mode (MODE = VCC), REFIN sets the voltage that FB regulates to.
In non-DDR mode (MODE = GND), connect REFIN to REF.
Shutdown Control. Low disables the switching regulator. SHDN and MODE select the operational
mode of the MAX1515.
SHDN
MODE Description
15
SHDN Low
Low Step-down regulator and REFOUT OFF
Low High Step-down regulator OFF, REFOUT active
High
Low Step-down regulator ON, non-DDR mode, REFOUT OFF
High
High Step-down regulator ON, DDR mode, REFOUT active
Mode-Select Pin. Mode sets the regulator into DDR mode or non-DDR operation mode, and controls
16
MODE
the REFOUT buffer. When MODE = VCC, MAX1515 is set in DDR mode and REFOUT is active. When
MODE = GND, MAX1515 is set in non-DDR mode and REFOUT is disabled. See the Modes of
Operation (MODE) section.
17 FBSEL0 Used with FBSEL1 to set the output voltage of the step-down regulator when MODE = GND.
Connect to GND if MODE = VCC.
______________________________________________________________________________________ 11
11 Page | ||
| Páginas | Total 24 Páginas | |
| PDF Descargar | [ Datasheet MAX1515.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MAX151 | 300kHz 10-Bit A/D Converter with Refrence and T/H |  Maxim Integrated |
| MAX1510 | Low-Voltage DDR Linear Regulator | Maxim Integrated Products |
| MAX15101 | Low-Dropout Linear Regulator | Maxim Integrated Products |
| MAX15102 | Low-Dropout Linear Regulator | 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 |