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Voltage Regulator. CM3121 Datasheet

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Voltage Regulator. CM3121 Datasheet
















CM3121 Regulator. Datasheet pdf. Equivalent













Part

CM3121

Description

Dual Linear Voltage Regulator



Feature


PRELIMINARY CM3121 Dual Linear Voltage R egulator for DDR-I and DDR-II Memory Fe atures Fully integrated power solution for DDR memory ICs • Ideal for DDR-I (2.5VDDQ) and DDR-II (1.8VDDQ) • Lowe st system cost and smallest footprint w ith just two external output capacitors • Two linear regulators: -V regulato r with a maximum output current www.Dat aSheet4U.com DDQ of 1.5A.
Manufacture

California Micro Devices

Datasheet
Download CM3121 Datasheet


California Micro Devices CM3121

CM3121; shared by DRAM and VTT regulator - sour ce-sink VTT regulator with maximum outp ut current of 0.5A (DDR-I) or 0.3A (DDR -II) • Fault output indicates overcur rent condition in either regulator, und er voltage lock-out and overtemperature condition • Reverse current protecti on if host is powered off • PSOP-8 pa ckage with integrated heat spreader • Lead-free versions availa.


California Micro Devices CM3121

ble • Product Description The CM3121 provides an integrated power solution f or DDR-I and DDR-II memory systems in c onsumer electronics applications. The C M3121 is ideal for a 2.8V to 3.6V suppl y for DDR-I memory and 2.2V to 2.8V for DDR-II memory. The CM3121 features two independent linear regulators for VDDQ and VTT supply regulation. The default voltage for VDDQ is.


California Micro Devices CM3121

2.5V. The VDDQ regulator SENSE pin allo ws for setting VDDQ in the 2.2V to 2.8V range, or DDR-II memories from 1.7V to 1.9V. The VTT regulator output is alwa ys half the VDDQ voltage, derived inter nally. A capacitor should be connected to each of the two outputs. When EN_DDR is set high, the two DDR regulators ar e disabled to minimize overall system p ower dissipation s.





Part

CM3121

Description

Dual Linear Voltage Regulator



Feature


PRELIMINARY CM3121 Dual Linear Voltage R egulator for DDR-I and DDR-II Memory Fe atures Fully integrated power solution for DDR memory ICs • Ideal for DDR-I (2.5VDDQ) and DDR-II (1.8VDDQ) • Lowe st system cost and smallest footprint w ith just two external output capacitors • Two linear regulators: -V regulato r with a maximum output current www.Dat aSheet4U.com DDQ of 1.5A.
Manufacture

California Micro Devices

Datasheet
Download CM3121 Datasheet




 CM3121
PRELIMINARY
CM3121
Dual Linear Voltage Regulator for DDR-I and DDR-II Memory
Features
• Fully integrated power solution for DDR memory
ICs
• Ideal for DDR-I (2.5VDDQ) and DDR-II (1.8VDDQ)
• Lowest system cost and smallest footprint with just
two external output capacitors
• Two linear regulators:
www.DataSheet4U.como- fV1D.D5QA
regulator with a maximum output current
shared by DRAM and VTT regulator
- source-sink VTT regulator with maximum out-
put current of 0.5A (DDR-I) or 0.3A (DDR-II)
• Fault output indicates overcurrent condition in
either regulator, under voltage lock-out and over-
temperature condition
• Reverse current protection if host is powered off
• PSOP-8 package with integrated heat spreader
• Lead-free versions available
Applications
• DDR-I and DDR-II memory power for:
Set Top Boxes, DVD Players, Games
Digital TVs, Flat Panel Displays
Printers, Digital Projectors
Embedded systems
Communications systems
Product Description
The CM3121 provides an integrated power solution for
DDR-I and DDR-II memory systems in consumer electron-
ics applications. The CM3121 is ideal for a 2.8V to 3.6V
supply for DDR-I memory and 2.2V to 2.8V for DDR-II mem-
ory. The CM3121 features two independent linear regula-
tors for VDDQ and VTT supply regulation. The default
voltage for VDDQ is 2.5V. The VDDQ regulator SENSE pin
allows for setting VDDQ in the 2.2V to 2.8V range, or DDR-II
memories from 1.7V to 1.9V. The VTT regulator output is
always half the VDDQ voltage, derived internally. A capacitor
should be connected to each of the two outputs.
When EN_DDR is set high, the two DDR regulators are dis-
abled to minimize overall system power dissipation such as
when memory is in standby.
The FAULT pin goes low whenever either of the two regula-
tors goes into current limit mode, the input voltage drops too
far or if overtemp occurs.
The CM3121 is available in a PSOP-8 package that has
excellent thermal dissipation. It is available with optional
lead-free finishing.
.
Typical Application Circuit
2.8V to 3.3V
VCC
CCC
Enable DDR
Memory #
EN_DDR
VREF
R
R
VDDQ
REGULATOR
VDDQ
VDDQ = 2.5V
SENSE
VDDQ
VTT
REGULATOR
VTT
CDDQ
VTT=1.25V
DDR
MEMORY
SENSE VTT
CTT
Circuit Schematic
VCC
VREF
EN_DDR
R
R
VDDQ
REGULATOR
VDDQ
SENSE
VDDQ
VDDQ
SENSE_ VDDQ
VTT
REGULATOR
VTT
SENSE VTT
VTT
SENSE_VTT
CURRENT LIMIT
OVERTEMP
LOW INPUT
GND
FAULT
CPU
CORE
+ I/O
CURRENT LIMIT
OVERTEMP
LOW INPUT
GND
FAULT
© 2004 California Micro Devices Corp. All rights reserved.
11/12/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.calmicro.com
1




 CM3121
PRELIMINARY
CM3121
Functional Description
The CM3121 provides power for DDR-I/DDR-II memo-
ries from two voltage regulators on-chip. There is an
over-temperature thermal shutdown if any of the regu-
lators overheat. Each regulator also has reverse cur-
rent protection in the event of any being shut down.
The VDDQ linear regulator can provide 2.5V/1.8V for
DDR-I/-II memory at up to 1.5A. An external feedback
resistor divider R1 and R2, when connected to the
www.DataSheeSvt4oEUltN.acSogmeEs_VfrDoDmQ2p.2inV,
enables selection of VDDQ output
to 2.8V for use with DDR-I memo-
ries requiring other than 2.5V for VDDQ (see Figure 5).
In this mode, the voltage on VDDQ is detemined as fol-
lows:
VDDQ = 1.25V x (---R----1-R--+--2--R----2---)-
When SENSE_VDDQ is connected to GND or left open,
VDDQ is fixed at 2.50V (and VTT at 1.25V). For DDR-II
operation, VDDQ can be set from 1.7V to 1.9V. The VTT
regulator is a linear source-sink regulator powered
from the VDDQ output that supplies the VTT supply
required by DDR-I memory termination resistors. This
regulator sinks or sources up to 0.5A. The VTT output
voltage accurately tracks VDDQ/2 to 1%. When there is
no VCC provided, VTT is powered down and its output
is 0V. This regulator has overload current limiting of
0.6A minimum.
The EN_DDR pin when set active low enables the
CM3121 to operate in normal mode with VDDQ and VTT
active. When EN_DDR is high, the CM3121 is disabled
and both VDDQ and VTT are set to 0V.
The FAULT output is normally at logic high but when
an overcurrent occurs on either VDDQ or VTT outputs,
FAULT goes active low, and remains low as long as
the overcurrent fault persists. Also if the chip goes into
thermal overload, or the input voltage VCC drops suffi-
ciently that the chip goes into Under Voltage Lock-Out
mode (UVLO), FAULT goes active low, and remains
low as long as the condition persists.
Note: This drawing is not to scale.
PACKAGE / PINOUT DIAGRAM
TOP VIEW
VCC
VDDQ
VTT
GND
1
2
3
4
8 SENSE_VDDQ
7 FAULT
6 SENSE_VTT
5 EN_DDR
8-Lead PSOP
LEAD
1
2
3
4
5
6
7
8
PAD
NAME
VCC
VDDQ
VTT
GND
EN_DDR
SENSE_VTT
FAULT
SENSE_VDDQ
GND
PIN DESCRIPTIONS
DESCRIPTION
Input supply.
VDDQ output.
VTT output for termination resistors or VREF
Ground reference.
Enable DDR power. Active low input.
Sense input for VTT rail adjustment.
Overcurrent Fault / UVLO indication, active low output.
Sense input for VDDQ rail adjustment.
Tied to ground reference.
© 2004 California Micro Devices Corp. All rights reserved.
2 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.calmicro.com 11/12/04




 CM3121
PRELIMINARY
CM3121
Ordering Information
PART NUMBERING INFORMATION
Leads
8
Package
PSOP-8
Standard Finish
Ordering Part
Number1
Part Marking
CM3121-02SB
CM3121 02SB
Lead-free Finish
Ordering Part
Number1
Part Marking
CM3121-02SH
CM3121 02SH
Note 1: Parts are shipped in Tape & Reel form unless otherwise specified.
www.DataSheet4U.com
Specifications
ABSOLUTE MAXIMUM RATINGS
PARAMETER
ESD (Human Body Model)
Pin Voltages
VCC
EN_DDR, SENSE_VDDQ, SENSE_VTT
Storage Temperature Range
Operating Temperature Range
Ambient
Junction
RATING
±2000
[GND - 0.6] to [+6.5]
[GND - 0.6] to [VCC + 0.6]
-40 to +150
-40 to +85
0 to +125
UNITS
V
V
V
°C
°C
°C
STANDARD OPERATING CONDITIONS
PARAMETER
RATING
UNITS
Ambient Operating Temperature Range
-40 to +85
°C
1. VDDQ Regulator
DDR-I Supply Voltage VCC
DDR-II Supply Voltage VCC
Load Current (note 1)
[VDDQ + 0.3] to 3.6
2.2 to 2.8
0 to 1500
V
V
mA
CCC, CDDQ
2. VTT Regulator
DDR-I Supply Voltage VDDQ
DDR-II Supply Voltage VDDQ
DDR-I Load Current
10, 10
2.3 to 2.8
1.7 to 1.9
0 to ±500
µF
V
V
mA
DDR-II Load Current
0 to ±300
mA
CTT 47 µF
Note 1: The VDDQ regulator provides power for both the memory load and the VTT regulator, supplying a total of 1.5A to the VDDQ
and VTT outputs. For example, if the VDDQ load current is 1.2A, then the maximum VTT load current will be 0.3A, regardless
of the actual VTT output current rating.
© 2004 California Micro Devices Corp. All rights reserved.
11/12/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.calmicro.com
3




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