Datasheet
Package Availability, Models, Samples & Pricing
| Obsolete Part | Alternate Part or
Supplier | Source | Last Time Buy Date |
LM27961TL
| LM2756
| National Semiconductor
| 30 Nov 2009
|
LM27961TLX
| LM2756
| National Semiconductor
| 30 Nov 2009
|
General Description
The LM27961 is a charge-pump-based white-LED driver that is ideal for mobile phone display backlighting. It is intended to drive 4 LEDs for a main phone display backlight and 3 LEDs for a sub-display backlight. Regulated internal current sources deliver excellent current and brightness matching in all LEDs.
The LED driver current sources are split into two independently controlled groups. The primary group (Group A) can be used to backlight a main phone display with up to 4 LEDs. The low-side current drivers of Group A accommodate common-anode-type LEDs. The second group (Group B) can backlight a secondary display with up to 3 LEDs. The high-side current drivers of Group B accommodate common-cathode-type LEDs. Both Group A and Group B can also drive standard two-terminal LEDs, and provide other general lighting functions (keypad lighting, fun lighting, etc). The brightness of the two LED groups can be adjusted independently with external resistors.
The LM27961 works off an extended Li-Ion input voltage range (2.7V to 5.5V). Voltage boost is achieved with a high-efficiency 3/2×-gain charge pump.
The LM27961 is available in National's chip-scale 18-bump micro SMD package.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
|
LM27961TL | CS065 | 2 | 38968 | 52 | 0 | 4402000 | 1 | 1249079519
|
|
LM27961TLX | CS065 | 2 | 38968 | 52 | 0 | 4402000 | 1 | 1249079519
|
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR.
The Long Term Failure Rates were calculated
at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress
temperature of 150°C to an application temperature of 55°C.
For more information on Reliability Metrics, please click here.
Application Notes
| Title | Size in Kbytes |
Date |
 |
| AN-1362: Application Note 1362 LM27961- Dual-Display White LED Driver with 3/2x Switched Capacitor Boost |
625
Kbytes |
30-Jun-05 |
Download |
AN-1362 (Chinese): Application Note 1362 LM27961- Dual-Display White LED Driver with 3/2x Switched Capacitor Boost
|
276 Kbytes |
|
 |
More Application Notes
| Title | Size in Kbytes |
Date |
|
| AN-1321: Application Note 1321 LM2796 Evaluation Board |
453
Kbytes |
25-May-04 |
Download |
| AN-1582: Application Note 1582 LM27965 Dual Display White LED Driver with I2C Compatible Brightness Control |
1226
Kbytes |
18-Mar-07 |
Download |
AN-1582 (Chinese): Application Note 1582 LM27965 Dual Display White LED Driver with I2C Compatible Brightness Control
|
503 Kbytes |
|
|
[Information as of 8-Nov-2009]
|
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