NSC LM2612BTLX, LM2612BTL, LM2612BBLX, LM2612BBL, LM2612ATLX Datasheet

December 2002

LM2612BL
400mA Sub-miniature, Programmable, Step-Down DC-DC
Converter for Ultra Low-Voltage Circuits

LM2612BL 400mA Sub-miniature, Programmable, Step-Down DC-DC Converter for Ultra

Low-Voltage Circuits

General Description

The LM2612 step-down DC-DC converter is optimized for
powering ultra-low voltage circuits from a single Lithium-Ion
cell. It provides up to 400mA (300mA for B grade), over an
input voltage range of 2.8V to 5.5V. Pin programmable out­put voltages of 1.05V, 1.3V, 1.5V or 1.8V allow adjustment
for MPU voltage options without board redesign or external
feedback resistors.

The device has three pin-selectable modes for maximizing
battery life in mobile phones and similar portable applica­tions. Low-noise PWM mode offers 600kHz fixed-frequency
operation to reduce interference in RF and data acquisition
applications during full-power operation. In PWM mode, in­ternal synchronous rectification provides high efficiency
(91% typ. at 1.8V
the switching frequency in a range of 500kHz to 1MHz to
avoid noise from intermodulation with system frequencies.
Low-current hysteretic PFM mode reduces quiescent current
to 160 µA (typ.) during system standby. Shutdown mode
turns the device off and reduces battery consumption to

0.02µA (typ.). Additional features include soft start and cur­rent overload protection.

The LM2612 is available in a 10 pin micro SMD packge. This
package uses National’s wafer level chip-scale micro SMD
technology and offers the smallest possible size. Only three
small external surface-mount components, an inductor and
two ceramic capacitors are required.

). A SYNC input allows synchronizing

OUT

Key Specifications

n Operates from a single LiION cell (2.8V to 5.5V)
n Internal synchronous rectification for high PWM mode

efficiency

n Pin programmable output voltage (1.05V, 1.3V, 1.5V and

1.8V)

n 400mA maximum load capability (300mA for B grade)

±

n

2% PWM mode DC output voltage precision

n 5mV typ PWM mode output voltage ripple
n 160 µA typ PFM mode quiescent current
n 0.02µA typ shutdown mode current
n 600kHz PWM mode switching frequency
n SYNC input for PWM mode frequency synchronization

from 500kHz to 1MHz

Features

n Sub-miniature 10-pin micro SMD package
n Only three tiny surface-mount external components

required

n Uses small ceramic capacitors
n Internal soft start
n Current overload protection
n No external compensation required
n Thermal shutdown protection

Applications

n Mobile Phones
n Hand-Held Radios
n Battery Powered Devices

Typical Application Circuit

20041802

© 2002 National Semiconductor Corporation DS200418 www.national.com

Connection Diagrams

micro SMD package

LM2612BL

TOP VIEW

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BOTTOM VIEW

Ordering Information

Order Number Package Type NSC Package

Marking(*)

10-Pin micro SMD

LM2612ABL

LM2612BBL XYTT IS41B 250 Units, Tape and Reel

LM2612ABLX XYTT IS41A 3000 Units, Tape and Reel

10-bump Wafer Level Chip Scale

LM2612BBLX XYTT IS41B 3000 Units, Tape and Reel

(*) XY - denotes the date code marking (2 digit) in production
TT - refers to die run/lot traceability for production
I - pin one indication
S - Product line designator
Note the Package Marking may change over the course of production time without notice

BLP106WB

(micro SMD)

XYTT IS41A 250 Units, Tape and Reel

Order Number Package Type NSC Package

Marking(*)

10-Pin micro SMD

LM2612ATL

LM2612BTL XYTT IS41B 250 Units, Tape and Reel

LM2612ATLX XYTT IS41A 3000 Units, Tape and Reel

10-bump Wafer Level Chip Scale

LM2612BTLX XYTT IS41B 3000 Units, Tape and Reel

(*) XY - denotes the date code marking (2 digit) in production
TT - refers to die run/lot traceability for production
I - pin one indication
S - Product line designator
Note the Package Marking may change over the course of production time without notice

TLP106WA

(micro SMD)

XYTT IS41A 250 Units, Tape and Reel

Supplied As

Supplied As

20041805

Pin Description

Pin Number Pin Name Function

A1 FB Feedback Analog Input. Connect to the output at the output filter capacitor (Figure 1)

B1 VID1 Output Voltage Control Inputs. Set the output voltage using these digital inputs (see Table

C1 VID0

D1 SYNC/MODE Synchronization Input. Use this digital input for frequency synchronization or modulation

D2 EN Enable Input. For shutdown, set low to SGND.(See Shutdown Mode in the Device

D3 PGND Power Ground

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1). The output defaults to 1.5V if these pins are unconnected.

control. Set:
SYNC/MODE = high for low-noise 600kHz PWM mode
SYNC/MODE = low for low-current PFM mode
SYNC/MODE = 500kHz - 1MHz external clock for synchronization to an external clock in
PWM mode. See Synchronization and Operating Modes in the Device Information section.

Information section.)

Pin Description (Continued)

Pin Number Pin Name Function

C3 SW Switching Node connection to the internal PFET switch and NFET synchronous rectifier.

B3 PVIN Power Supply Input to the internal PFET switch. Connect to the input filter capacitor

(Figure 1).

A3 VDD Analog Supply Input. If board layout is not optimum, an optional 0.1µF ceramic capacitor

is suggested (Figure 1)

A2 SGND Analog and Control Ground

(*) Note that the pin numbering scheme for the Micro SMD package was revised in April, 2002 to conform to JEDEC standard. Only the pin numbers were revised.
No changes to the physical location of the inputs/outputs were made. For reference purpose, the obselete numbering had FB as pin 1, VID1 as pin 2, VID0 as pin
3, SYNC as pin 4, EN as pin 5, PGND as pin 6, SW as pin 7, PVIN as pin 8, VDD as pin 9 and SGND as pin 10.

LM2612BL

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/

LM2612BL

Distributors for availability and specifications.

PVIN, VDD, to SGND −0.2V to +6V

PGND to SGND −0.2V to +0.2V

EN, SYNC/MODE, VID0, VID1 to
SGND −0.2V to +6V

FB, SW (GND −0.2V) to

Lead temperature
(Soldering, 10 sec.) 260˚C

Junction Temperature (Note 2) −25˚C to 125˚C

Minimum ESD Rating
Human body model, C = 100pF, R =

1.5 kΩ

Thermal Resistance (θ

)

JA

LM2612ABL/LM2612ATL &
LM2612BBL/LM2612BTL(Note 3) 140˚C/W

(VDD +0.2V)

Storage Temperature Range −45˚C to +150˚C

Electrical Characteristics

Specifications with standard typeface are for TA=TJ= 25˚C, and those in bold face type apply over the full Operating Tem­perature Range (T
0V.

Symbol Parameter Conditions Min Typ Max Units

V

V

V

IN

FB

HYST

Input Voltage Range (Note4)PVIN = VDD = VID1 = VIN,

Feedback Voltage
(Note 5)

PFM Comparator Hysteresis
Voltage
(Note 6)

I

SHDN

I

Q1

I

Q2

R

DSON (P)

Shutdown Supply Current EN = 0V 0.02 3 µA

DC Bias Current into VDD No switching, PFM mode

Pin-Pin Resistance for P
FET

R

DSON (N)

Pin-Pin Resistance for N
FET

R

DSON , TC

FET Resistance
Temperature Coefficient

I

lim

Switch Peak Current Limit
(Note 7)

V

EN_H

EN Positive Going
Threshold Voltage

V

EN_L

EN Negative Going
Threshold Voltage

V

SYNC_H

SYNC/MODE Positive
Going Threshold Voltage

V

SYNC_L

SYNC/MODE Negative
Going Threshold Voltage

V

ID_H

V

ID0,VID1

Threshold Voltage

V

ID_L

V

ID0,VID1

Threshold Voltage

I

VID

VID1, VID0 Pull Down
Current

= −25˚C to +85˚C). Unless otherwise specified, PVIN = VDD = EN = SYNC = 3.6V, VID0 = VID1 =

A=TJ

VID0 = 0V

VID0 = V

VID0 = V

, VID1 = V

IN

, VID1 = 0V 1.274 1.30 1.326

IN

IN

2.8 5.5 V

1.029 1.05 1.071

VID0 = 0V, VID1 = 0V 1.470 1.50 1.530

VID0 = 0V, VID1 = V

IN

1.764 1.8 1.836

PFM Mode (SYNC = 0V)

25 mV

(SYNC/MODE = 0V)

No switching, PWM mode
(SYNC/MODE = V

)

IN

160 195

605 725

395 550 mΩ

325 500 mΩ

0.5 %/C

LM2612ABL/LM2612ATL 510 710 850

LM2612BBL/LM2612BTL 400 710 980

0.95 1.3 V

0.4 0.80 V

0.95 1.3 V

0.4 0.84 V

Positive Going

Negative Going

0.4 0.83 V

VID1, VID0 = 3.6V

0.92 1.3 V

1.8 3.0 µA

±

2kV

V

µA

mA

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Electrical Characteristics (Continued)

Specifications with standard typeface are for TA=TJ= 25˚C, and those in bold face type apply over the full Operating Tem­perature Range (T
0V.

Symbol Parameter Conditions Min Typ Max Units

f

sync

SYNC/MODE Clock
Frequency Range
(Note 8)

F

OSC

Internal Oscillator
Frequency

T

min

Minimum ON-Time of P FET
Switch in PWM Mode

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended
to be functional, but parameter specifications may not be guaranteed. For guaranteed specifications and associated test conditions, see the Min and Max limits and
Conditions in the Electrical Characteristics table. Electrical Characteristics table limits are guaranteed by production testing, design or correlation using standard
Statistical Quality Control methods. Typical (Typ) specifications are mean or average values from characterization at 25˚C and are not guaranteed.

Note 2: Thermal shutdown will occur if the junction temperature exceeds the 150˚C maximum junction temperature of the device.

Note 3: Thermal resistance specified with 2 layer PCB(0.5/0.5 oz. cu).

Note 4: The LM2612 is designed for applications where turn-on after system power-up is controlled by the system processor and internal UVLO (Under Voltage

LockOut) circuitry is unnecessary. The LM2612 has no UVLO circuitry and should be kept in shutdown by holding the EN pin low until the input voltage exceeds 2.8V.
Although the LM2612 exhibits safe behavior while enabled at low input voltages, this is not guaranteed.

Note 5: The feedback voltage is trimmed at the 1.5V output setting. The other output voltages result from the pin selection of the internal DAC’s divider ratios. The
precision for the feedback voltages is

Note 6: : The hysteresis voltage is the minimum voltage swing on FB that causes the internal feedback and control circuitry to turn the internal PFET switch on and
then off during PFM mode.

Note 7: Current limit is built-in, fixed, and not adjustable. If the current limit is reached while the output is pulled below about 0.7V, the internal PFET switch turns
off for 2.5 µs to allow the inductor current to diminish.

Note 8: SYNC driven with an external clock switching between V
external clock frequency. The LM2612 synchronizes to the rising edge of the external clock.

= −25˚C to +85˚C). Unless otherwise specified, PVIN = VDD = EN = SYNC = 3.6V, VID0 = VID1 =

A=TJ

500 1000 kHz

LM2612ABL/ATL, PWM Mode
(SYNC = VIN)

LM2612BBL/BTL, PWM Mode
(SYNC = VIN)

468 600 732

450 600 750

200 nS

±

2%.

and GND. When an external clock is present at SYNC, the IC is forced to PWM mode at the

IN

LM2612BL

kHz

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Typical Operating Characteristics LM2612ABL/ATL, Circuit of Figure 1,V

10 µH, unless otherwise noted.

LM2612BL

Quiescent Supply Current vs Temperature Quiescent Supply Current vs Supply Voltage

= 3.6V, TA= 25˚C, L1=

IN

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20041807

Shutdown Quiescent Current vs Temperature Output Voltage vs Temperature (PWM Mode)

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20041809

Output Voltage vs Supply Voltage

Output Voltage vs Temperature (PFM Mode)

(V

= 1.5V, PWM Mode)

OUT

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