sc643 Semtech Corporation, sc643 Datasheet
sc643
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sc643 Summary of contents
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... October 8, 2009 Light Management Unit with 4 LDOs and SemPulse Description The SC643 is a high effi ciency charge pump LED driver using Semtech’s proprietary charge pump technology. Performance is optimized for use in single cell Li-ion battery applications. Display backlighting is provided through fi ve matched current sinks with integrated fade-in and fade-out con- trols ...
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... Semtech Lot No. Ordering Information Device SC643ULTRT SC643EVB 16 Notes: LDO1 15 (1) Available in tape and reel only. A reel contains 3,000 devices. (2) Lead-free packaging only. Device is WEEE and RoHS compliant, LDO2 14 and halogen free. BYP 13 12 SPIF LDO3 11 10 SC643 Package (1)(2) MLPQ-UT-20 3×3 Evaluation Board 2 2 ...
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... Min Typ 2.9 = 4.2V 0.1 ( (2) 300 IN = 0.5mA, 5 LEDs on 2.5 = 25mA, 5 LEDs on 4.3 = 25mA, 5 LEDs on 5.1 BLn 125 0 -8 ±1.5 -3.5 ±0.5 = 3.2V 3.22 OUT = 3.2V 250 OUT SC643 T +85 ≤ ≤ 5.5 ≤ ≤ 5.25 ≤ ≤ OUT ≤ 1.0 F (°C/ 4.7μF, IN OUT Max Units 5.5 V 2.0 μA 135 μA 450 ...
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... V 150 LDOm 100 LDO2 D2 200 2.1 = 2.8V LDOm 1.3 = 1.8V LDO2 = 22nF, BYP 50 supply ripple P-P = 22nF, BYP 60 supply ripple P-P = 22nF, BYP = 50 mA, 75 < 3.0V = 22nF, BYP = 50 mA, 50 < 1.8V 1 LDOn SC643 Max Units μA kHz 3 +3.5 % 200 mV 150 mA 7 μV RMS μ ...
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... Decreasing V UVLO V UVLO-HYS - BL(MIN) BL(MAX) BL(MIN) Min Typ 1 0.75 0.75 500 500 10 10 300 165 5.7 OUT OVP 2.4 IN 300 =3.2V for white LEDs. OUT SC643 Max Units V 0 μA +1 μA ms 250 μs 250 μs 5000 μs μ °C °C 6 ...
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... Backlight Effi ciency (5 LEDs) — 25mA Each V = 3.65V 125mA, 25 °C OUT OUT 4.2 3.9 3.6 3.3 V (V) IN Backlight Effi ciency (5 LEDs) — 12mA Each V = 3.45V 60mA, 25 °C OUT OUT 4.2 3.9 3.6 3.3 V (V) IN Backlight Effi ciency (5 LEDs) — 5.0mA Each V = 3.28V 25mA, 25°C OUT OUT 4.2 3.9 3.6 3.3 V (V) IN SC643 3.0 2.7 3.0 2.7 3.0 2 ...
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... IN OUT OUT 0 10 100 1000 Frequency (Hz) Line Regulation (LDOm 1mA, 25° 1.5V to 3.3V LDOm LDOm 2. 4.2 3.9 3.3 3.6 V (V) IN LDO Noise vs. Load Current — 2.8V V =2.8V, V =3.7V, 25°C, 10Hz < f < 100kHz LDO (mA) OUT SC643 10000 3.0 2.7 120 150 7 7 ...
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... Load Regulation (LDOm) V =3.6V, 25° 1.5V 1.8V 2.5V 2.8V 3. 120 I (mA) LDO LDO Load Transient Response (1.2V) V =3.7V, V =1.2V 100mA, 25°C IN LDO LDO Time (20μs/div) Output Short Circuit Current Limit V =0V, V =4.2V, 25°C OUT IN (1V/div) Time (1ms/div) SC643 160 200 8 8 ...
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... OUT I (20mA/div) BL Time (20μs/div) Ripple — 1.5X Mode V =3.6V, 5 Backlights — each, 25° (50mV/div (100mV/div) OUT I (20mA/div) BL Time (20μs/div) Output Open Circuit Protection V =3.7V, 25° (500mV/div) BL 5.42V V (1V/div) OUT I (20mA/div) BL Time (200μs/div) SC643 9 9 ...
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... Charge pump output — all LED anode pins should be connected to this pin Positive connection to bucket capacitor 2 Positive connection to bucket capacitor 1 Negative connection to bucket capacitor 1 Negative connection to bucket capacitor 2 Thermal pad for heatsinking purposes — connect to ground plane using multiple vias — not con- nected internally SC643 10 10 ...
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... Voltage Reference 2 PGND AGND 9 8 ENL4 C2+ C1+ C1- C2 Fractional Charge Pump (1x, 1.5x, 2x) Oscillator Current Setting DAC Voltage Setting DAC V IN LDO2 V IN LDO4 SC643 16 OUT 5 BL1 4 BL2 3 BL3 6 BL4 7 BL5 V IN LDO1 15 LDO1 14 LDO2 V IN LDO3 11 LDO3 10 LDO4 11 11 ...
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... For backlight applications using fewer than fi ve LEDs, any unused output must be left open and the unused LED must remain disabled. When writing to the backlight enable register, a zero (0) must be written to the corre- sponding bit of any unused output. SC643 ) of F LED mis-match ...
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... Main/Sub Backlight Fade register (09h). This procedure must be followed regardless of which backlight grouping confi guration is being used. Note that it is only necessary to set the BLEN bits for the main or sub display that is required to fade. SC643 Immediate bright level No Write ...
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... Additional Information For more details about the Fade-in/Fade-out function, refer to the SC643 Backlight Driver Software User’s Guide and SemPulse Interface Specifi cation document and to the associated software drivers available for this device (contact your sales offi ce for more details). ...
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... In sleep mode, the SemPulse interface continues to monitor its input for commands from the host. Typical current consumption in this mode is 90μA. Protection Features The SC643 provides several protection features to safe- guard the device from catastrophic failures. These features include: • Output Open Circuit Protection • ...
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... Applications Information (continued) PCB Layout Considerations The layout diagram in Figure 2 illustrates a proper two- layer PCB layout for the SC643 and supporting components. Following fundamental layout rules is critical for achieving the performance specified in the Electrical Characteristics table. The following guidelines are recommended when developing a PCB layout: • ...
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... This safeguard is intended to reset the bus to a known state (waiting for the beginning of a write sequence) if the delay exceeds the reset threshold. SC643 , the bus will expect the next HOLDD exceeds its HOLDA — ...
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... HI HOLDA t < t HImax Address is set to Data written is register 02h 000010 Interrupt duration t > HImax HOLDA SC643 Data is written HOLDD t LO Data written is 000011 HOLDD t < t LOmax Address is set to register 03h (address and data are now out of order) ...
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... LDO2V0 LDO3V3 LDO3V2 LDO3V1 LDO3V0 LDO4V3 LDO4V2 LDO4V1 LDO4V0 SFADE MFADE1 MFADE0 MFADE (3) 0 MB2 MB1 MB0 SC643 Reset Description Value 00h Backlight Enable 00h Main Backlight Current 00h Sub Backlight Current 00h LDO1 00h LDO2 00h LDO3 00h LDO4 00h ...
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... This bit is unused and is always a zero See note (1) 0 See note (1) 1 See note ( SC643 20 20 ...
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... Table 6 — LDO1 Control Codes LDO1V2 LDO1V1 LDO1V0 SC643 V LDO1 OFF 3.3V 3.2V 3.1V 3.0V 2.9V 2.8V 2.7V 2.6V 2.5V 2.4V 2.2V 1.8V 1.7V 1.6V 1. ...
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... Table 8 — LDO3 Control Codes LDO3V3 LDO3V2 LDO2 0 1 OFF SC643 LDO3V1 LDO3V0 V LDO3 0 0 OFF ...
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... MFADE1 and MFADE0 bits. 0 1.8V The total fade time is given by the number of steps 1 1.7V between old and new backlight values (see Table 4), mul- 0 1.6V tiplied by the rate of fade in ms/step. 1 1.5V Fade Feature Rise/ MFADE0 Fall Rate (ms/step SC643 ...
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... Main Display Sub Display MB1 MB0 LED Drivers LED Drivers 0 1 BL1 - BL5 1 0 BL1 - BL4 1 1 BL1 - BL3 0 0 BL1 - BL2 0 1 BL1 BL1 - BL5 (default) SC643 none BL5 BL4 - BL5 BL3 - BL5 BL2 - BL5 none 24 24 ...
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... MIN NOM MAX MIN NOM MAX - - A .020 .024 0.50 0. .000 .002 0.00 0.05 (.006) (0.152 .006 .008 .010 0.15 0.20 0.25 D .114 .118 .122 2.90 3.00 3.10 D1 .061 .067 .071 1.55 1.70 1.80 E .114 .118 .122 2.90 3.00 3.10 E1 .061 .067 .071 1.55 1.70 1.80 e .016 BSC 0.40 BSC L .012 .016 .020 0.30 0.40 0. aaa .003 0.08 bbb .004 0.10 SC643 25 25 ...
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... Tel: 86-21-6391-0830 Fax: 86-21-6391-0831 Japan Tel: 81-3-6408-0950 Fax: 81-3-6408-0951 DIM Switzerland United Kingdom France Germany www.semtech.com SC643 DIMENSIONS INCHES MILLIMETERS (.114) (2.90) .083 2.10 .067 1.70 .067 1.70 .016 0.40 .004 0.10 .008 0.20 .031 0.80 .146 3.70 Tel: 41-32-729-4000 Fax: 41-32-729-4001 Tel: 44-1794-527-600 ...