MIC2827 Triple Output PMIC with HyperLight Load™ DCDC, two LDOs, and I2C Control General Description The Micrel MIC2827 is a three output, programmable Power Management IC, optimized for high efficiency power support in Mobile Application Processors, CoProcessors, DSPs, GPS and Media Player chipsets. The device integrates a single 500mA PWM/PFM synchronous buck (step-down) regulator with two Low Dropout Regulators and a 400kHz I²C interface that provides programmable Dynamic Voltage Scaling (DVS), Power Sequencing, and individual output Enable/Disable controls allowing the user to optimally control all three outputs. The 4MHz synchronous buck regulator features a patented HyperLight Load™ (HLL) architecture which minimizes switching losses and provides low quiescent current operation for high efficiency at light loads. Additional benefits of this proprietary architecture are low output ripple voltage and fast transient response throughout the entire load range with the use of small output capacitors, reducing the overall system size. Two high performance LDOs are integrated into the MIC2827 to provide additional system voltages for I/O, memory and other analog functions. Each LDO is capable of sourcing 150mA output current with high PSRR and low output noise. A 2% output voltage accuracy, low dropout voltage (150mV @ 150mA), and low ground current of 83µA (both LDOs operating) makes this device ideally suited for mobile applications. The MIC2827 is available in a tiny 14-pin 2.5mm x 2.5mm Thin MLF® with a junction operating range from -40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Applications • • • • • • Application processors GPS subsystems General purpose PMIC Mobile phones / PDAs Portable media players Mobile television receivers Features • • • • • • • Fast-mode I2C control interface Tiny 14-pin 2.5mm x 2.5mm MLF® package Default start-up voltage states and sequencing Fault indication processor flag - IRQb -40°C to 125°C junction temperature range Thermal shutdown and current-limit protection Power On After Fault (POAF) function DC-DC Synchronous Buck • 2.7V to 5.5V input voltage range • 500mA continuous output current • HyperLight Load™ mode – 25µA quiescent current • 90% peak efficiency; 85% at 1mA • Ultra-fast transient response • Dynamic Voltage Scaling (DVS) range: 0.8V to 1.8V – 0.8V to 1.2V in 25mV steps – 1.2V to 1.8V in 50mV steps • ±3% over temperature • Low output voltage ripple: 20mVpp in HyperLight Load™ mode, 3mV in full PWM mode LDOs • 1.8V to VDVIN input voltage range • 150mA output current (each LDO) • Dynamic Voltage Scaling (each LDO) – DVS range: 0.8V to 3.3V in 50mV steps • ±3% over temperature • Low quiescent current – 50µA (each LDO) • Low dropout voltage – 50mV @ 50mA • Low output noise - 45µVRMS • Stable with ceramic output capacitors • 65dB PSRR at 1kHz HyperLight Load is a trademark of Micrel, Inc MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com July 2009 M9999-072709-A Micrel, Inc. MIC2827 Typical Application July 2009 2 M9999-072709-A Micrel, Inc. MIC2827 Ordering Information Marking Code (2) Part Number MIC2827-B2YMT 827B2 Default Start Up Voltages (1) Default Start Up Sequence (1) Junction Temp. Range DC-DC LDO1 LDO2 DC-DC LDO1 LDO2 1.8V 1.2V 2.8V 1 2 3 -40°C to +125°C Package (3) 14-Pin 2.5x2.5mm Thin MLF® Note: 1. Other Default voltages and sequences are available on request (Voltages: 0.8V to 3.3VOUT LDOs, and 0.8V to 1.8VOUT PWM). Please contact Micrel Marketing for other voltage ranges. ® 2. Thin MLF Pin 1 Identifier symbol is “▲”. ® 3. Thin MLF is a Green RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. July 2009 3 M9999-072709-A Micrel, Inc. MIC2827 Pin Configuration ® 14-Pin 2.5mm x 2.5mm Thin MLF (MT) (Top View) Pin Description Pin Number Pin Name Pin Function 1 LDO1OUT Output of LDO1: Requires a minimum 1µF ceramic capacitor-to-AGND. 2 LDO2OUT 3 LDO2IN July 2009 Output of LDO2: Requires a minimum 1µF ceramic capacitor-to-AGND. External Input Supply Rail to LDO2. Requires a minimum 1µF ceramic capacitor to AGND. 4 N/C 5 IRQb 6 SW 7 DGND Switch Ground Pin. 8 DVIN Input Voltage: Requires a close minimum 2.2µF ceramic capacitor to DGND. 9 SDA Fast-mode 400kHz I²C Data Input/Output pin. 10 SCL Fast-mode 400kHz I²C Clock Input pin. Fault Output (open drain). Switch (Output): Internal power MOSFET output switches. 11 FB 12 AGND Feedback Pin Connected to VOUT to sense output voltage. 13 EN Enable (Input): Executes default startup sequence. Active High. HIGH = ON, LOW = OFF. Do not leave floating. The EN pin function is optional if I2C control is used for startup and shutdown. 14 LDO1IN External Input Supply Rail to LDO1. Requires a minimum 1µF ceramic capacitor to AGND. EP HS PAD Exposed Heat-Sink Pad. Analog Ground. Must be connected externally to DGND. 4 M9999-072709-A Micrel, Inc. MIC2827 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDVIN, VLDO1IN, VLDO2IN)............ -0.3V to +6V Enable Voltage (VEN) ....................................... -0.3V to +6V I2C Voltage (VSDA, VSCL) ................................... -0.3V to +6V Power Dissipation ................................. Internally Limited(3) Lead Temperature (Soldering, 10 sec.) ..................... 260°C Storage Temperature (TS)...................–65°C ≤ TJ ≤ +150°C ESD Rating(4) ................................................................. 2kV DVIN Supply voltage (VDVIN)......................... +2.7V to +5.5V LDO Supply voltage (VLDO1IN, VLDO2IN) ............+1.8V to VDVIN Enable Input Voltage (VEN)..................................0V to VDVIN I2C Voltage (VSDA, VSCL) .................................... 0V to +5.5V Junction Temperature Range (TJ)............. –40°C to +125°C Junction Thermal Resistance 2.5mm x 2.5mm Thin MLF-14 (θJA) ...................89°C/W Electrical Characteristics(5) – DC/DC Converter DVIN = EN = 3.6V; LDO1, LDO2 disabled; L=1µH, COUT =4.7µF, IOUT= 20mA, TA = 25°C, unless otherwise specified. Bold values indicate -40°C≤TJ≤+125°C. Parameter Conditions Min 2.7 Supply Voltage Range Under-Voltage Lockout Threshold Rising Switcher Quiescent Current, HLL IOUT = 0mA, FB > 1.2 * VOUT Nominal Shutdown Current EN = 0V, DVIN = 5.5V Output Voltage Accuracy DVIN = 3.6V; ILOAD = 20mA Current Limit in PWM Mode FB = 0.9* VOUT(NOM) Output Voltage Line Regulation Output Voltage Load Regulation PWM Switch ON-Resistance Typ 2.45 Units 5.5 V 2.55 2.65 V 25 35 µA 2 5 µA +3 % -3 0.55 Max 1 A DVIN = 3.0V to 5.5V, ILOAD = 20mA 0.4 %/V 20mA < ILOAD < 500mA, DVIN = 3.6V 0.5 % ISW = 100mA PMOS 0.55 Ω ISW = -100mA NMOS 0.6 Ω 4 MHz 300 µs Frequency ILOAD = 120mA SoftStart Time VOUT = 90% Enable Voltage OFF 0.2 1.2 ON 2 V Enable Input Current 0.1 Over-temperature Shutdown 160 °C Over-temperature Shutdown Hysteresis 20 °C VOUT Ramping Up 91 % VOUT Ramping Down 89 % 280 Ω VPOR Threshold % of VOUT below Nominal Auto-Discharge NFET resistance µA Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. 4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF. 5. Specification for packaged product only. July 2009 5 M9999-072709-A Micrel, Inc. MIC2827 Electrical Characteristics - LDO1, LDO2 DVIN = EN = LDO1IN = LDO2IN = 3.6V; DC-DC disabled; LDO COUT =1µF, LDO IOUT = 100µA, TA = 25°C, unless otherwise specified. Bold values indicate -40°C≤TJ≤+125°C. Parameter Conditions Min Output Voltage Accuracy Variation from nominal VOUT -3.0 Input voltage IOUT = 100µA to 150mA; Typ Max Units +3.0 % 2 V IOUT = 100µA to 100mA; -20°C to +100°C 1.74 V Output Voltage DVS Range Adjustable through I²C Registers 0.8 Line Regulation LDO1IN, LDO2IN = VOUT +1V to 5.5V; IOUT = 100µA Load Regulation IOUT = 100µA to 75mA Dropout Voltage IOUT = 50mA; VOUT = 2V 70 IOUT = 150mA; VOUT = 2V 200 IOUT = 50mA; VOUT = 3V 50 mV IOUT = 150mA; VOUT = 3V 150 mV 1 LDO enabled 50 µA 2 LDOs enabled 83 µA f = up to 1kHz; COUT = 1µF; VOUT = 2.5V 65 dB f = 1kHz - 10kHz; COUT = 1µF VOUT = 2.5V 45 dB Ground Pin Current Ripple Rejection 0.014 3.3 V 0.1 %/V 4 mV mV 350 mV EN = DVIN Current Limit VOUT = 0V Output Voltage Noise COUT = 1µF,10Hz to 100kHz 190 Auto-Discharge NFET resistance 400 550 mA 45 µVRMS 280 Ω Electrical Characteristics – I2C Interface DVIN = EN = 3.6V, TA = 25°C, unless otherwise specified. Bold values indicate -40°C≤TJ≤+125°C. Parameter Conditions Min Typ LOW-Level Input Voltage 1.2 HIGH-Level Input Voltage Max Units 0.2 V V SDA Pull-down resistance Open drain pull-down on SDA during read back 80 Ω IRQb Pull-down resistance Open drain pull-down 55 Ω July 2009 6 M9999-072709-A Micrel, Inc. MIC2827 Typical Characteristics Enable Threshold v s. Input Voltage Enable Threshold v s. Temperature 2.0 0.9 0.9 1.8 0.8 0.8 1.6 0.7 0.7 1.4 ENABLE THRESHOLD (V) ENABLE THRESHOLD (V) OUTPUT VOLTAGE (V) Thermal Shutdown 0.6 1.2 0.5 1.0 0.4 0.8 0.3 0.6 0.2 DVIN = 3.6V VIN = 3.6V VOUT = 1.8V 0.4 0.2 0.1 0.6 0.5 0.4 0.3 0.2 0.1 DVIN = VIN = 3.6V 0 0 0.0 -40 0 40 80 120 160 T EM PERAT URE (°C) -40 200 -20 0 20 40 60 80 T EM PERAT URE (°C) 2.7 100 120 3.1 LDO Output Noise Spectral Density LDO Input Voltage PSRR 5.1 5.5 Dropout Voltage v s. Load Current 10 90 3.5 3.9 4.3 4.7 INPUT VO LT AGE (V) 250 80 70 NO ISE (µV/√Hz) 40 DVIN = 5.5V VIN = 3.6V VOUT = 1.2V COUT = 1µF Load = 150mA 20 10 0 0.01 DVIN = VIN = 5.5V VOUT = 1.0V COUT = 1µF Load = 10mA VLDO = 3V 100 0 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 FREQ UENCY (Hz) FREQ UENCY (Hz) 0 Dropout Voltage v s. Tem perature L = 150mA DRO POUT VOLTAGE (mV) 175 150 L = 100mA 100 75 50 L = 50mA 25 0 DVIN = 5.5V VLDO = 2V COUT = 1µF -20 0 20 40 60 80 T EM PERAT URE (°C) 125 100 L = 100mA 75 50 25 DVIN = 5.5V VLDO = 3V COUT = 1µF L = 50mA 1.8 1.230 1.6 OUTPUT VO LTAGE (V) 2.0 1.240 1.220 1.210 1.200 1.190 1.180 1.170 DVIN = 5.0 VIN = 3.6V COUT = 1µF 1.160 1.150 0 July 2009 25 50 75 100 125 LOAD CURRENT (mA) -20 0 20 40 60 80 T EM PERAT URE (°C) 1.22 1.21 1.20 1.19 1.18 DVIN = VIN = 3.6V VOUT = 1.2V COUT = 1µF Load = 100µA 1.17 1.16 -40 100 120 1.4 1.2 1.0 0.8 0.6 DVIN = 5.5V VLDO = 1.8V COUT = 1µF Load = 100µA 0.4 0.2 0.0 150 150 1.23 -20 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 INPUT VO LT AG E (V) 7 0 20 40 60 80 100 120 TEM PERATURE (°C) LDO Current Limit v s. Input Voltage LDO Output Voltage v s. Input Voltage 1.250 125 1.15 -40 LDO Output Voltage v s. Load Current 100 1.24 L = 150mA 150 100 120 75 LDO Output Voltage v s. Temperature 0 -40 50 1.25 175 200 125 25 LO AD CURRENT (mA) 200 225 50 DVIN = 5.5V COUT = 1µF 0.001 250 DROPOUT VOLTAG E (mV) 150 Noise = (10Hz to 100kHz)=44.77µVRMS Dropout Voltage v s. Temperature OUTPUT VOLTAGE (V) VLDO = 2V LDO OUTPUT VOLTAGE (V) 30 0.1 200 CURRENT LIM IT (mA) PSRR (dB) 50 DROPOUT VOLTAGE (mV) 1 60 700 650 600 550 500 450 400 350 300 250 200 150 100 50 0 DVIN =5.5V COUT = 1µF 2 2.5 3 3.5 4 4.5 INPUT VOLT AGE (V) 5 5.5 M9999-072709-A Micrel, Inc. MIC2827 Typical Characteristics (continued) 55 440 53 430 51 420 410 400 390 380 370 0 20 40 60 80 TEM PERATURE (°C) 100 47 45 43 41 DVIN = VIN = 3.6V VOUT = 1.2V COUT = 1µF Load = 150mA 39 35 350 -20 100 49 37 DVIN = VIN = 3.6V -40 120 LDO Ground Current v s. Load Current -20 0 20 40 60 80 T EM PERAT URE (°C) 100 120 1 LDO VOUT = 1.2V COUT = 1µF Load = 100µA 20 2.7 90 90 51.2 85 85 80 49.6 49.2 48.8 75 70 VIN=4.2V 60 DVIN = VIN = 3.6V VOUT = 1.2V COUT = 1µF 48.4 VIN=3.6V 65 L = 1µH C = 4.7µF 50 75 100 125 LO AD CURRENT (mA) 150 1 DC-DC Efficiency VOUT=1.5V 90 VIN=2.7V 85 10 100 LO AD CURRENT (mA) 1000 DC-DC Switching Frequency v s. Load Current 90 EFFICIENCY (%) 80 VIN=4.2V 70 60 50 L = 1µH C = 4.7µF 55 10 100 LOAD CURRENT (mA) 10 SW FREQ UENCY (M Hz) L=4.7µH L=1µH DVIN = 3.6V VOUT = 1.8V 10 100 LOAD CURRENT (mA) 1 VOUT = 1.8V L = 1µH 5.0 4.5 4.6 4.0 4.4 4.2 4.0 3.8 DVIN = 3.6V VOUT = 1.8V L = 1µH C= 4.7µF Load = 120mA 3.6 3.4 10 100 LOAD CURRENT (mA) 3.5 3.0 2.5 2.0 1.5 VOUT = 1.8V L = 1µH C= 4.7µF Load = 120mA 1.0 0.5 0.0 -40 -20 0 20 40 60 80 T EM PERAT URE (°C) 8 100 120 1000 DC-DC Switching Frequency v s. Input Voltage 4.8 3.0 1000 1000 5.0 3.2 0.01 10 100 LOAD CURRENT (mA) VIN=4.2V DC-DC Switching Frequency v s. Temperature DC-DC Switching Frequency v s. Load Current L=2.2µH VIN=3.6V 0.1 0.01 1 1000 VIN=3.0V 1 L = 1µH C = 4.7µF 40 50 July 2009 100 VIN=3.6V 60 1 10 LOAD CURRENT (mA) 10 VIN=2.7V 65 0.1 L = 1µH C = 4.7µF 1 100 70 1 VIN=4.2V 65 DC-DC Efficiency VOUT=1.8V VIN=3.6V VIN=4.2V 1 70 1000 80 75 75 50 SW FREQUENCY (M Hz) 25 5.5 VIN=2.7V 55 50 0 5.1 60 55 48.0 3.5 3.9 4.3 4.7 INPUT VOLT AGE (V) VIN=3.6V 80 VIN=2.7V EFFICIENCY (%) EFFICIENCY (%) 50.0 3.1 DC-DC Efficiency VOUT=1.2V SW FREQUENCY (M Hz) G ROUND CURRENT (µA) 40 51.6 50.4 EFFICIENCY (%) 2 LDOs 60 DC-DC Efficiency VOUT=1.0V 50.8 SW FREQUENCY (M Hz) 80 0 -40 120 GROUND CURRENT (µA) 450 360 LDO Ground Current v s. Input Voltage LDO Ground Current v s. Temperature GROUND CURRENT (µA) CURRENT LIMIT (mA) LDO Current Limit v s. Temperature 2.7 3.1 3.5 3.9 4.3 4.7 INPUT VOLT AGE (V) 5.1 5.5 M9999-072709-A Micrel, Inc. MIC2827 Typical Characteristics (continued) DC-DC Output Voltage v s. Load Current DC-DC Output Voltage v s. Input Voltage DC-DC Output Voltage v s. Tem perature 1.92 1.9 1.90 1.88 1.88 OUTPUT VOLTAGE (V) O UTPUT VOLTAGE (V) 1.84 1.82 1.80 1.78 1.76 1.74 VIN = 3.6V L = 1µH C= 4.7µF 1.72 1.70 1.84 1.82 1.8 1.78 1.76 1.74 100 200 300 400 LOAD CURRENT (mA) DVIN = 3.6V VOUT = 1.8V Load = 20mA 1.72 1.7 1.68 0 OUTPUT VOLTAGE (V) 1.86 1.86 -40 500 -20 DC-DC Current Lim it v s. Input Voltage 0 20 40 60 80 T EM PERAT URE (°C) 2.10 2.06 2.02 1.98 1.94 1.90 1.86 1.82 1.78 1.74 1.70 1.66 1.62 1.58 1.54 1.50 100 120 L = 1µH C= 4.7µF Load = 20mA 2.7 3.1 5.1 5.5 RDSON (PMOS) v s. Temperature Current Limit v s. Tem perature 1.2 3.5 3.9 4.3 4.7 INPUT VOLT AGE (V) 1.40 800 1.20 700 1.1 CURRENT LIM IT (A) CURRENT LIM IT (A) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 VOUT = 1.8V L = 1µH C= 4.7µF 0.2 0.1 0.0 2.7 3.1 3.5 3.9 4.3 4.7 INPUT VO LT AGE (V) 5.1 600 1.00 RDS (mΩ) 1.0 0.80 0.60 0.40 DVIN = 3.6V VOUT = 1.8V 300 100 0 0.00 -40 -20 RDSON (NMOS) v s. Temperature 0 20 40 60 80 T EM PERAT URE (°C) -40 100 120 800 700 700 600 600 500 500 RDS (mΩ) 500 400 300 RDS (mΩ) 800 800 600 400 300 300 200 200 100 100 100 0 0 -20 0 20 40 60 80 T EM PERAT URE (°C) 100 120 2.7 28 30 25 20 15 DVIN = 3.6V VOUT = 1.8V IOUT = 0mA 0 July 2009 -20 0 20 40 60 80 T EM PERAT URE (°C) 100 120 Q UIESCENT CURRENT (µA) QUIESCENT CURRENT (µA) 29 35 -40 3.5 3.9 4.3 4.7 5.1 5.5 2.7 3.1 3.5 3.9 4.3 4.7 INPUT VOLT AGE (V) 5.1 5.5 Quiescent Current v s. Input Voltage 40 5 3.1 INPUT VOLTAGE (V) Quiescent Current v s. Tem perature 10 100 120 400 200 0 0 20 40 60 80 T EM PERAT URE (°C) RDSON (NMOS) v s. Input Voltage 900 -40 -20 RDSON (PMOS) v s. Input Voltage 700 RDS (mΩ) 400 200 0.20 5.5 500 27 26 25 24 23 22 21 VOUT = 1.8V IOUT = 0mA 20 19 2.7 3.1 3.5 3.9 4.3 4.7 INPUT VO LT AG E (V) 9 5.1 5.5 M9999-072709-A Micrel, Inc. MIC2827 Functional Characteristics July 2009 10 M9999-072709-A Micrel, Inc. MIC2827 Functional Characteristics (continued) July 2009 11 M9999-072709-A Micrel, Inc. MIC2827 Functional Block Diagram MIC2827 Block Diagram July 2009 12 M9999-072709-A Micrel, Inc. MIC2827 Power-Up via the EN Pin The EN pin is transition sensitive and not level sensitive (with the exception of hot enable—please see the description below). If the EN pin is toggled low-to-high, the MIC2827 will execute the default startup sequence. During the startup sequence, the appropriate set of supply enables is loaded into the Enable Register. This allows the part to present a consistent interface to the I²C host; if the host reads the Enable Control register, it will see one or more enables on, which is consistent with one or more active supplies. Individual control of the supplies is now possible via the I²C interface. Functional Description – Power Control and Sequencing Two Types of Part: Sequence-Enabled and NoSequence • Sequence-Enabled parts support automatic sequencing of the three supplies. SequenceEnabled parts all have a default sequence (activated by asserting the EN pin). These parts also allow sequencing to be disabled. While very flexible, sequence-enabled parts require more care in operation. See the later section “Ensuring Clean Switching in Sequence-Enabled Parts”. • No-Sequence parts have no built-in sequencing capability. Their default startup turns on only one supply, which requires no sequencing. If the host needs more supplies to come on, this can be accomplished with I²C writes which allows a sequence activated by software to be performed. “Hot Enable” Startup Some systems may choose to tie the EN pin to DVIN, so that the MIC2827 registers an active EN pin as it completes power-on. This is perfectly legal and produces a default startup immediately after power is applied. Depending on the rise time of the input power being applied, the UVLO flag may be set. Power-up State When battery power is first applied to the MIC2827, all I²C registers are loaded with their default (POR) values. If EN is high, a default startup is executed; otherwise, the part remains in a quiescent state waiting to be started by EN or an I²C command. Power-Down via the EN Pin If the EN pin is toggled high-to-low, then the MIC2827 will shut down all outputs simultaneously. For reasons similar to those above, at the conclusion of the shutdown sequence, all three individual supply enables will be clear in the Enable Control register and the bias will be switched off. If the MIC2827 startup is initiated by asserting EN and later shutdown is initiated by clearing the Enable Register bits, the part will be quiescent (with all bias currents disabled) but EN will still be high. In this case, de-asserting EN will have no effect, since the part has already completed its shutdown. Enable Pin-Initiated Default Startup When EN is asserted, a default startup is executed. This is defined below: • The voltage registers are loaded with their default values. • In sequence-enabled parts, the Sequence Control bit is set to low (to allow sequencing to occur). Nosequence parts always have zero for the Sequence Control bit • The correct set of supply enable bits is loaded into the Enable Register, and the appropriate sequence is then executed. • The Power-On After Fault (POAF) bit is set to its default state, high. Power-Up and Power-Down via the Enable Register The three individual power supply enable bits in the Enable Register (LDO2-EN, LDO1-EN, and DC-EN) may be used to enable and disable individual supplies. If the part is sequenced-enabled, and sequencing is permitted by the Sequence Control bit, enabled supplies are turned on in sequence. Any disabled outputs will not participate in the sequence and will be ignored. See also the “Ensuring Clean Switching in SequenceEnabled Parts” section. Under no circumstances should the EN and I²C control be used simultaneously. The results would not be deterministic. If a supply output is enabled and its Voltage Control register is written with a new value, the output voltage changes immediately at the I²C acknowledge. Turning on the Power Supplies After power is applied, the MIC2827 offers two methods of turning the three supply outputs on and off: 1. Default startup sequencing or shutdown via the EN pin; 2. Flexible startup sequencing or shutdown via the I²C interface July 2009 13 M9999-072709-A Micrel, Inc. MIC2827 Interrupt Operation If interrupts are enabled (INT-EN = 1), then the MIC2827’s IRQb output will be asserted (driven low) whenever either of the two fault bits, UVLO or TSD, are asserted. Clearing the fault status bit by writing a one to it will clear the interrupt if the fault condition is no longer present. If the fault is still present, the status bit will be asserted again, together with the IRQb output. This operation does not depend on the state of the POAF bit. The default state of the INT_EN bit is zero, so the interrupt output is disabled. This is done so that the interrupt pin does not transition in MIC2827 systems which use only the EN pin and not the I²C interface. Fault Handling A fault is generated from either a thermal shutdown or under-voltage lockout event. If a fault occurs, the activation of the fault condition immediately turns off all output supplies, sets the fault flag bit(s) in the Status Register, and loads default values in the Enable and Voltage Registers. The sequence Control bit SEQ CNT is cleared to enable sequencing for sequence-enabled parts. The POAF bit is unaffected. The default state of the Enable Register’s POAF (Power On After Fault) bit is high, indicating that the MIC2827 will perform a default start up when the fault goes away. If the user instead prefers that the part does not automatically attempt re-start after a fault, the POAF can be programmed to a “0”. The EN pin can be toggled high-to-low at any time to clear the supply enables in the Enable Register and shut down the part. The same can be achieved through I2C at any time by disabling all enables in the enable register. Either method can be used to shut down the part during a fault. Shutdown after a fault will maintain the fault flags in the status register. Only Power-on-Reset or an echo reset of the status register will clear these flags. Ensuring Clean Switching in Sequence-Enabled Parts In no-sequence parts, no sequencing ever occurs, and no special rules are required. However, in sequenceenabled parts, care must be taken when using automatic supply startup sequencing. The sequence-enabled MIC2827 accomplishes supply sequencing by asynchronously using one supply’s power good signal to enable the next supply in line. As a consequence “downstream” supplies can momentarily switch off their outputs when “upstream” supplies are switched in and out of the sequencing chain. Example: Suppose the sequence [DC, 1, 2] is enabled and LDO1 is off, the others are enabled and their status is valid. If LDO1 is now enabled through I²C, LDO2 will turn momentarily off, until LDO1 is valid, which then starts LDO2. To avoid this, the following rules should be observed, which apply only to sequence-enabled parts: 1. If all supplies are to be turned on, it is fine to use sequencing. This is what happens naturally as part of the EN-initiated default startup. It may also be accomplished by setting all three supply enables simultaneously in the Enable Register, and leaving the Sequence Control bit low to permit sequencing. 2. When starting from an all-off condition and a subset of the supplies is to be turned on, sequencing is permitted. 3. When one or more supplies are on, and a supply is to be turned off or on, sequencing must be disabled by setting SEQ CNT high. 4. When a subset of the supplies has been turned on via the Enable Register, an active transition on the EN pin must not be used to turn on the remaining supplies. Thermal Shutdown (TSD) If the MIC2827’s on-chip thermal shutdown detects that the die is too hot, the part will immediately turn off all outputs but maintain the bias to internal circuitry. The thermal event is logged in the Status register which can be read via I²C. When the thermal shutdown event is removed, a default startup is executed if POAF is high. Under Voltage Lock Out (UVLO) If the MIC2827’s on-chip voltage monitor detects a low voltage on the DVIN supply, the part will immediately turn off all outputs but maintain the bias to internal circuitry. When the UVLO event is removed, the outputs will turn on using the default startup if POAF is high. The UVLO event is logged in the status register which can be read via I²C. If the power on DVIN drops too low, the MIC2827 will no longer be able to function reliably and will enter its power-on reset (POR) state. Any previously raised TSD or UVLO flags will now be cleared at startup Power Good Indication and Hysteresis The status of all three outputs can be read via I²C in the status register. A register flag is set for each output when it reaches 90% of its regulated value and cleared when the output falls to about 85%. July 2009 14 M9999-072709-A Micrel, Inc. MIC2827 Sequencing rules do not apply to the last supply in the sequencing chain (the supply labeled “3rd” in the sequence table). The 3rd supply may be turned on and off at any time, since there are no downstream supplies from the 3rd. Available Default Startup Sequences The following table shows available default startup sequences for the MIC2827. Please contact Micrel factory to request customized default startup voltages and sequences. Sequence Number DC-DC LDO1 LDO2 SequenceEnabled Part? Sequence 2 1st 2nd 3rd Yes July 2009 15 M9999-072709-A Micrel, Inc. MIC2827 Functional Description – Fast-mode I²C Interface I²C Address The seven-bit I²C address of the MIC2827 is set at the factory to 1011010 binary, which would be identified as B4h using standard I²C nomenclature, in which the read/write bit takes the least significant position of the eight-bit address. Other I²C base addresses are available; please contact Micrel for details. Electrical Characteristics – Serial Interface Timing 3.0V ≤ VDVIN ≤ 3.6V unless otherwise noted. Bold values indicate -40°C ≤ TA ≤ +125°C. Symbol Parameter Conditions Min Typ Max Units t1 SCL (clock) period 2.5 µs t2 Data In Setup Time to SCL High 100 ns t3 Data Out Stable After SCL Low 0 ns t4 SDA Low Setup Time to SCL Low Start 100 ns t5 SDA High Hold Time after SCL High Stop 100 ns Serial Interface Timing July 2009 16 M9999-072709-A Micrel, Inc. MIC2827 the MIC2827, followed by a repeat of the device address with the R/W bit (LSB) set to the high (read) state. The data to be read from the part may then be clocked out. These protocols are shown in Figure 1 and Figure 2. The Register Address is eight bits (one byte) wide. This byte carries the address of the MIC2827 register to be operated upon. Only the lower three bits are used. Serial Port Operation The MIC2827 uses standard Write_Byte, Read_Byte, and Read_Word operations for communication with its host. The Write_Byte operation involves sending the device’s address (with the R/W bit low to signal a write operation), followed by the register address and the command byte. The Read_Byte operation is a composite write and read operation; the host first sends the device’s address followed by the register address, as in a write operation. A new start bit must then be sent to Figure 1: Write_Byte protocol Figure 2: Read_Byte protocol July 2009 17 M9999-072709-A Micrel, Inc. MIC2827 Enable/Startup Control Register (00h): The Enable Register is used to allow control of the MIC2827’s power supplies. It allows each supply to be turned on and off, and whether sequencing is used. When a default startup is executed as a result of the EN pin being taken from low to high, the Sequence Control, and Supply Enable bits are all set to their default values. The Sequence Control bit, only implemented in sequence-enabled parts, must be used carefully. See the section on “Ensuring Clean Switching in SequenceEnabled Parts”. Functional Description – I²C Control Registers Register Address Register Name Read/ Write 00h Enable R/W Enable and startup control register 01h Status R/W Regulator output & fault condition status register 02h DC-DC R/W DC-DC regulator voltage control register 03h LDO1 R/W LDO1 voltage control register 04h LDO2 R/W LDO2 voltage control register D7 Description D5 D4 D3 D2 D1 D0 Reserved POAF SEQ CNT Reserved LDO2-EN LDO1-EN DC-EN Access N/A R/W R/W N/A R/W R/W R/W POR Value 00 1 0 0 0 0 0 Data 00 0 = Remain off after fault 0 = Sequencing enabled 1 = Restore power after fault 1 = Sequencing disabled Yes Yes Yes Yes Yes No No Yes No Yes, if POAF=1 Name Set by Default Startup? Set by a fault? July 2009 D6 18 0 = Disable 1 = Enable M9999-072709-A Micrel, Inc. MIC2827 Status Register (01h): The Status Register allows the state of each supply to be interrogated, supports flags that are set when fault conditions occur, and controls the use of the MIC2827’s interrupt pin. D7 D6 D5 D4 D3 D2 D1 D0 Name Reserved INT-EN UVLO TSD Reserved L2-Status L1-Status DC-Status Access RO R/W Echo reset Echo reset RO RO RO RO POR Value 0 0 0 0 0 0 0 0 Data 0 0: Interrupt is disabled 0: Normal 0: Normal 0 1: DVIN undervoltage occurred 1: Thermal shutdown occurred 0 = LDO2 Not Valid 0 = LDO1 Not Valid 0 = DC-DC Not Valid 1 = LDO2 Valid 1 = LDO1 Valid 1 = DC-DC Valid 1: Interrupt is enabled Note: “Echo reset” bits remain set until cleared. Clearing these bits is accomplished by writing a one to that bit location (“echo the one to reset”). If the fault condition (UVLO or thermal shutdown) persists after the echo reset, the corresponding Status Register bit will be set high again immediately. July 2009 19 M9999-072709-A Micrel, Inc. MIC2827 DC-DC Regulator Voltage Control Register (02h) This register controls the output voltage of the DC-DC PWM/PFM Regulator. The DC-DC Regulator employs a dual scale voltage step size to cover a wide range of output voltages from 0.8V to 1.8V. From 0.8V to 1.2V a step size of 25mV allows maximum power saving when the Processor Core is placed into a light load state. From 1.2V to 1.8V, a step size of 50mV provides a wide range of output voltages for power system flexibility. DC-DC Regulator Voltage Control Register Table DC-DC Regulator Voltage Control Register Address: 02h Step Size Register Value Output Voltage 25mV 00h 0.800 01h 0.825 02h 0.850 03h 0.875 04h 0.900 05h 0.925 06h 0.950 07h 0.975 08h 1.000 09h 1.025 0Ah 1.050 0Bh 1.075 0Ch 1.100 0Dh 1.125 0Eh 1.150 0Fh 1.175 10h 1.200 11h 1.250 12h 1.300 13h 1.350 14h 1.400 15h 1.450 16h 1.500 17h 1.550 18h 1.600 19h 1.650 1Ah 1.700 1Bh 1.750 1Ch 1.800 50mV July 2009 20 M9999-072709-A Micrel, Inc. MIC2827 LDO1, LDO2 Voltage Control Registers Table LDO1 Regulator Voltage Control Register Address: 03h LDO2 Regulator Voltage Control Register Address: 04h Step Size Register Value Output Voltage Step Size Register Value Output Voltage 50mV 00h 0.800 50mV BAh 2.400 0Bh 0.850 BDh 2.450 14h 0.900 C1h 2.500 1Dh 0.950 C4h 2.550 25h 1.000 C7h 2.600 2Eh 1.050 C9h 2.650 37h 1.100 CCh 2.700 3Eh 1.150 CEh 2.750 45h 1.200 D1h 2.800 4Ch 1.250 D3h 2.850 52h 1.300 D6h 2.900 57h 1.350 D8h 2.950 5Ch 1.400 DAh 3.000 61h 1.450 DCh 3.050 65h 1.500 DEh 3.100 69h 1.550 E1h 3.150 6Dh 1.600 E3h 3.200 72h 1.650 E6h 3.250 79h 1.700 E8h 3.300 7Fh 1.750 July 2009 85h 1.800 8Bh 1.850 91h 1.900 96h 1.950 9Ah 2.000 9Fh 2.050 A4h 2.100 A8h 2.150 ACh 2.200 B0h 2.250 B4h 2.300 B7h 2.350 21 M9999-072709-A Micrel, Inc. MIC2827 LDO1OUT The LDO1OUT pin provides the regulated output voltage of LDO1. Power is provided by LDO1IN. LDO1OUT voltage can be dynamically scaled through I2C control. The recommended output capacitance is 1µF, decoupled to AGND. Functional Description DVIN The DVIN pin provides power to the source of the internal switch P-channel MOSFET, I2C control and voltage references for the MIC2827. The DVIN operating voltage range is from 2.7V to 5.5V. In order for any MIC2827 outputs to regulate, the appropriate input voltage must be applied to the DVIN pin. Due to the high switching speeds, a 4.7µF capacitor is recommended as close as possible to the DVIN and power ground (DGND) pin for bypassing. Please refer to layout recommendations. LDO2OUT The LDO2OUT pin provides the regulated output voltage of LDO2. Power is provided by LDO2IN. LDO2OUT voltage can be dynamically scaled through I2C control. The recommended output capacitance is 1µF, decoupled to AGND. LDO1IN LDO1IN provides power to the source of the LDO1 Pchannel MOSFET. The LDO1IN operating voltage range is from 1.8V to VDVIN. The recommended bypass capacitor is 1µF. SCL The I2C clock input pin provides a reference clock for clocking in the data signal. This is a fast-mode 400kHz input pin, and requires a 4.7kΩ pull-up resistor. Please refer to “Serial Port Operation” for more details. LDO2IN LDO2IN provides power to the source of the LDO2 Pchannel MOSFET. The LDO2IN operating voltage range is from 1.8V to VDVIN. The recommended bypass capacitor is 1µF. SDA The I2C data bidirectional pin allows for data to be written to and read from the MIC2827. This is a fastmode 400kHz I2C pin, and requires a 4.7kΩ pull-up resistor. Please refer to “Serial Port Operation” for more details. EN The enable pin controls the ON and OFF state of all the outputs of the MIC2827. The EN pin is transition sensitive and not level sensitive. By toggling the enable pin low-to-high, this activates the default startup sequence of the part. IRQb The IRQb (open drain) pin provides an interrupt for when either the UVLO or TSD faults are asserted. When enabled through I2C, the IRQb pin will assert together with the corresponding fault condition. Please refer to the “Interrupt Operation” for more details. SW The switching pin connects directly to one end of the inductor and provides the switching current during switching cycles. The other end of the inductor is connected to the load, output capacitor, and the FB pin. Due to the high speed switching on this pin, the switch node should be routed away from sensitive nodes. DGND Power ground (DGND) is the ground path for the DC-DC MOSFET drive current. The current loop for the Power ground should be as small as possible and separate from the Analog ground (AGND) loop. Refer to the layout consideration for more details. FB The feedback pin provides the control path to control the output. A recommended 4.7µF bypass capacitor should be connected in shunt with the DC-DC output. It is good practice to connect the output bypass capacitor to the DGND and FB should be routed to the top of COUT. July 2009 AGND Analog ground (AGND) is the ground path for the biasing and control circuitry. The current loop for the Analog ground should be separate from the Power ground (AGND) loop. Refer to the layout consideration for more details. 22 M9999-072709-A Micrel, Inc. MIC2827 The MIC2827 was designed for use with an inductance range from 0.47µH to 4.7µH. Typically, a 1µH inductor is recommended for a balance of transient response, efficiency and output ripple. For faster transient response a 0.47µH inductor may be used. For lower output ripple, a 4.7µH is recommended. Proper selection should ensure the inductor can handle the maximum average and peak currents required by the load. Maximum current ratings of the inductor are generally given in two methods; permissible DC current and saturation current. Permissible DC current can be rated either for a 40°C temperature rise or a 10% to 20% loss in inductance. Ensure the inductor selected can handle the maximum operating current. When saturation current is specified, make sure that there is enough margin that the peak current will not saturate the inductor. Peak current can be calculated as follows: Application Information The Micrel MIC2827 is a three output, programmable Power Management IC, optimized for high efficiency power support. The device integrates a single 500mA PWM/PFM synchronous buck (step-down) regulator with two Low Dropout Regulators and an I²C interface that provides programmable Dynamic Voltage Scaling (DVS), Power Sequencing, and individual output Enable/Disable controls allowing the user to optimally control all three outputs. Input Capacitors A 4.7µF ceramic capacitor is recommended on the DVIN pin for bypassing. X5R or X7R dielectrics are recommended for the input capacitor. Y5V dielectrics lose most of their capacitance over temperature and are therefore not recommended. Also, tantalum and electrolytic capacitors alone are not recommended because of their reduced RMS current handling, reliability, and ESR increases. An additional 0.1µF is recommended close to the DVIN and DGND pins for high frequency filtering. Smaller case size capacitors are recommended due to their lower ESR and ESL. Minimum 1.0µF ceramic capacitors are recommended on the LDO1IN and LDO2IN pins for bypassing. Please refer to layout recommendations for proper layout of the input capacitors. ⎡ ⎛ 1 − VOUT /VIN ⎞⎤ IPEAK = ⎢IOUT + VOUT ⎜ ⎟⎥ ⎝ 2 × f × L ⎠⎦ ⎣ As shown by the previous calculation, the peak inductor current is inversely proportional to the switching frequency and the inductance; the lower the switching frequency or the inductance the higher the peak current. As input voltage increases, the peak current also increases. The size of the inductor depends on the requirements of the application. Refer to the Application Circuit and Bill of Material for details. DC resistance (DCR) is also important. While DCR is inversely proportional to size, DCR can represent a significant efficiency loss. Refer to the Efficiency Considerations. Output Capacitors The MIC2827 is designed for a 2.2µF or greater ceramic output capacitor for the DC-DC converter and 1.0µF for the LDO regulators. Increasing the output capacitance will lower output ripple and improve load transient response but could increase solution size or cost. A low equivalent series resistance (ESR) ceramic output capacitor such as the TDK C1608X5R0J475K, size 0603, 4.7µF ceramic capacitor is recommended based upon performance, size and cost. X5R or X7R dielectrics are recommended for the output capacitor. Y5V dielectrics lose most of their capacitance over temperature and are therefore not recommended. In addition to a 4.7µF, a small 0.1µF is recommended close to the load for high frequency filtering. Smaller case size capacitors are recommended due to their lower equivalent series ESR and ESL. Efficiency Considerations Efficiency is defined as the amount of useful output power, divided by the amount of power supplied. ⎛V ×I Efficiency % = ⎜⎜ OUT OUT V IN × IIN ⎝ Maintaining high efficiency serves two purposes. It reduces power dissipation in the power supply, reducing the need for heat sinks and thermal design considerations and it reduces consumption of current for battery powered applications. Reduced current draw from a battery increases the devices operating time and is critical in hand held devices. There are two types of losses in switching converters; DC losses and switching losses. DC losses are simply the power dissipation of I2R. Power is dissipated in the high side switch during the on cycle. Power loss is equal to the high side MOSFET RDSON multiplied by the Switch Current squared. During the off cycle, the low side Nchannel MOSFET conducts, also dissipating power. Device operating current also reduces efficiency. The Inductor Inductor selection will be determined by the following (not necessarily in the order of importance); • Inductance • Rated current value • Size requirements • DC resistance (DCR) July 2009 ⎞ ⎟⎟ × 100 ⎠ 23 M9999-072709-A Micrel, Inc. MIC2827 product of the quiescent (operating) current and the supply voltage is another DC loss. The current required driving the gates on and off at a constant 4MHz frequency and the switching transitions make up the switching losses. PMOS on and keeps it on for the duration of the minimum-on-time. This increases the output voltage. If the output voltage is over the regulation threshold, then the error comparator turns the PMOS off for a minimumoff-time until the output drops below the threshold. The NMOS acts as an ideal rectifier that conducts when the PMOS is off. Using a NMOS switch instead of a diode allows for lower voltage drop across the switching device when it is on. The asynchronous switching combination between the PMOS and the NMOS allows the control loop to work in discontinuous mode for light load operations. In discontinuous mode, the MIC2827 works in pulse frequency modulation (PFM) to regulate the output. As the output current increases, the off-time decreases, thus providing more energy to the output. This switching scheme improves the efficiency of MIC2827 during light load currents by only switching when it is needed. As the load current increases, the MIC2827 goes into continuous conduction mode (CCM) and switches at a frequency centered at 4MHz. The equation to calculate the load when the MIC2827 goes into continuous conduction mode may be approximated by the following formula: Efficiency VOUT=1.8V 100 VIN=3.6V 90 EFFICIENCY (%) 80 70 VIN=2.7V 60 VIN=4.2V 50 40 30 20 10 0 1 10 100 LOAD CURRENT (mA) 1000 The Figure above shows an efficiency curve. From no load to 100mA, efficiency losses are dominated by quiescent current losses, gate drive and transition losses. By using the HyperLight Load™ mode the MIC2827 is able to maintain high efficiency at low output currents. Over 100mA, efficiency loss is dominated by MOSFET RDSON and inductor losses. Higher input supply voltages will increase the Gate-to-Source threshold on the internal MOSFETs, thereby reducing the internal RDSON. This improves efficiency by reducing DC losses in the device. All but the inductor losses are inherent to the device. In which case, inductor selection becomes increasingly critical in efficiency calculations. As the inductors are reduced in size, the DC resistance (DCR) can become quite significant. The DCR losses can be calculated as follows: DCR Loss = IOUT2 × DCR From that, the loss in efficiency due to inductor resistance can be calculated as follows: ⎛ (V − VOUT ) × D ⎞ ILOAD > ⎜ IN ⎟ 2L × f ⎝ ⎠ As shown in the previous equation, the load at which MIC2827 transitions from HyperLight Load™ mode to PWM mode is a function of the input voltage (VIN), output voltage (VOUT), duty cycle (D), inductance (L) and frequency (f). This is illustrated in the graph below. Since the inductance range of MIC2827 is from 0.47µH to 4.7µH, the device may then be tailored to enter HyperLight Load™ mode or PWM mode at a specific load current by selecting the appropriate inductance. For example, in the graph below, when the inductance is 4.7µH the MIC2827 will transition into PWM mode at a load of approximately 5mA. Under the same condition, when the inductance is 1µH, the MIC2827 will transition into PWM mode at approximately 70mA. Switching Frequency v s. Load Current ⎡ ⎛ ⎞⎤ VOUT × IOUT ⎟⎟⎥ × 100 Efficiency Loss = ⎢1 − ⎜⎜ ⎣⎢ ⎝ VOUT × IOUT + L_PD ⎠⎦⎥ 10 L=4.7µH SW FREQUENCY (M Hz) Efficiency loss due to DCR is minimal at light loads and gains significance as the load is increased. Inductor selection becomes a trade-off between efficiency and size in this case. HyperLight Load Mode™ The MIC2827 uses a minimum on and off time proprietary control loop (patented by Micrel). When the output voltage falls below the regulation threshold, the error comparator begins a switching cycle that turns the July 2009 1 L=2.2µH L=1µH 0.1 DVIN =3.6V VOUT = 1.8V 0.01 1 24 10 100 LO AD CURRENT (mA) 1000 M9999-072709-A Micrel, Inc. MIC2827 Recommended Schematic Bill of Materials Item Part Number C1, C2, C3, C5 GRM155R61A105KE15D C6, C7 R2, R3 Capacitor, 1µF, 10V, X5R, 0402 size C1005X5R0J105KT TDK(2) Capacitor, 1µF, 10V, X5R, 0402 size GRM188R60J475K Murata(1) TDK (2) Qty. 4 Capacitor, 4.7µF, 6.3V, X5R, 0603 size 2 Capacitor, 4.7µF, 6.3V, X5R, 0603 size CRCW040210K0FKEA Vishay(3) Resistor, 10kΩ, 1%, 1/16W, 0402 size 2 CRCW04024K70FKEA (3) Resistor, 4.7kΩ, 1%, 1/16W, 0402 size 2 (4) Connector, 2.54mm (0.1”) Pitch PCB Connector, 4 circuits 1 JP1 0022152046 L1 LQM21PN1R0MC0 MLP2520S1R0L U1 Description Murata(1) C1608X5R0J475M R1, R4 Manufacturer Vishay Molex Murata(1)) Inductor, 1.0µH, 0.8A, 2.0 x 1.25 x 0.5mm TDK(2) Inductor, 1.0µH, 1.5A, 2.5 x 2.0 x 1.0mm (5 XPL2010-102ML Coilcraft CIG21W1R0MNE Samsung MIC2827-xxYMT (6) Micrel, Inc.(7) 1 Inductor, 1.0µH, 1.1A, 2.0 x 1.9 x 1.0mm Inductor, 1.0µH, 1.05A, 2.0 x 1.25 x 1.0mm Triple Output PMIC with HyperLight Load™ DC-DC, Two LDOs, and I2C Control 1 Notes: 1. Murata Tel: www.murata.com. 2. TDK: www.tdk.com. 3. Vishay Tel: www.vishay.com. 4. Molex.: www.molex.com. 5. Coilcraft: www.coilcraft.com. 6. Samsung: www.sem.samsung.com. 7. Micrel, Inc.: www.micrel.com. July 2009 25 M9999-072709-A Micrel, Inc. MIC2827 Recommended Layout Top Layout Bottom Layout July 2009 26 M9999-072709-A Micrel, Inc. MIC2827 Package Information 14-Pin 2.5mm x 2.5mm Thin MLF® (MT) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2009 Micrel, Incorporated. July 2009 27 M9999-072709-A