AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset General Description
The AT1368 provides complete control and protection for a DC/DC converter optimized for high-performance microprocessor applications. It is designed to drive one P-Channel and one NChannel MOSFETs in a synchronous-rectified buck topology. The AT1368 integrates all of the control, output adjustment, monitoring and protection functions into a single package. The output voltage of the converter can be precisely regulated with a maximum tolerance of ±2% over temperature and line voltage variations. The AT1368 is a family of low-noise synchronous stepdown DC/DC converters that is ideally suited for systems powered from a 1-cell Li-ion battery or from a 3-cell to 4-cell NiCd, NiMH, or alkaline battery. It can also be used to USB-Based power system.
Features
• High efficiency (min. 90% On IO=300mA ~600mA) • Using external P and N channel MOSFET • Supports for down and up/down Zeta conversion • Maximum Duty 100% • Oscillation frequency 300KHz or 600KHz • Soft Start by an external capacity • Output voltage accuracy ±2% • Built-in ON/OFF Function • Built-in Short-circuit Protection • Stand-by current max. 10µA • Quiescent Current 1mA • Monitor the input voltage and 3V3 output • Input voltage: 2.5V ~7.0V
Applications
• Slim-Type CD-ROM/DVD-ROM/CD-RW • Power Supply for portable devices • Main or Sub Power source foe notebook computers and peripherals.
Block Diagram
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 1
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Pin Configuration
Ordering Information
Part number AT1368A AT1368B AT1368B Package SSOP16 SSOP16 TSSOP16 Marking AT1368AR AT1368BR AT1368BP
A: fosc =300KHz B: fosc =600KHz
Pin Description
Symbol Pin No. Descript Symbol Pin No.(A/B) Descript
FB COMP PVCC PDRV NDRV PGND GND VCC
1 2 3 4 5 6 7 8
Inverting input to error amplifier Error amplifier output Power blocks power supply Output for Pch-MOSFET Output for Nch-MOSFET Power blocks ground Control blocks ground Control blocks power supply
SCP CTL NC IN1 RESET IN2 SS 3V3
9 10 11 12 13 14 15 16
Short-Circuit protection Chip enable, high active VCC monitor voltage adjustable input pin Power Good indicator 3V3 output monitor adjustable input pin Sotf-start Output voltage 3.3V
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 2
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Absolute Maximum Ratings
Parameter Power Supply Voltage Source Average Current of PDRV, NDRV Sink Average Current of PDRV, NDRV Source Peak Current of PDRV, NDRV Sink Peak Current of PDRV, NDRV Input Voltage to Error Amplifier Continuous power dissipation Operating temperature Storage temperature Condition — — — — — — SSOP16(Ta=+25℃) — — Rated Value Min. Max. +8 -50 -30 -55 50 -200 200 6.5 560 +85 +125 Unit V mA mA mA mA V mW 0 C 0 C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Recommended Operating Conditions
(Ta=+250C)
Parameter Power supply voltage Control input voltage Operating temperature
Symbol VCC VCTL TOP Min. 2.5 0 -20
Values Typ. --+25 Max. 7 7 +85
Unit V V °C
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 3
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Electrical Characteristics
(VCC = 5V,Ta =+25℃ , unless otherwise noted. )
Parameter Input Supply Range Quiescent Current Current in standby mode Entire device Reference Voltage Reference Voltage line-regulation Rference Variation with Temperature Input Offset Voltage Source Current Sink Current Source current Variation with temperature Sink current Variation with temperature Unity Gain Bandwidth Common Mode Input Voltage Range DC Open Loop Gain Frequency Sawtooth wave oscillator (OSC) High Level Voltage Low Level Voltage Variation with Power Supply Variation with temperature Charge Current of SS Invalid threshold voltage of SS Charge Current of SS Threshold Voltage of SCP
Symbol VCC ICC IST VREF VREF-Line
Condition 2.5 Duty=50%, fOSC=600KHz PDRV/NDRV No Load CTL=0V Ta =-20℃ to +85℃ VCC=2.5V to 7.0V Ta =-20℃ to +85℃
Values Min. Typ. Max. -1.0 7.0 1.5 10 1.20 1.22 1.24 1 0.5 1.0 1.5 -160 -120 5 1.5 10 2.0 -80 20 20 10.0 0.2 1.5 110 300 600 1.0 0.5
Unit V mA µA V mV % mV mA μA % % MHz V dB 350 KHz 700 KHz V V 2 7 % % µA V µA V
VIO IOH IOL
VCOMP = VREF -0.5V VCOMP = 0.5V Ta =-20℃ to +85℃ Ta =-20℃ to +85℃
Error amplifier
fT VCOM AV fosc fosc AT1368A AT1368B 250 500
Vcc=2.5V to 7V Ta =-20℃ to +85℃ ICSS -1.0 1.0 ICSS -1.25 1.0
Soft-Start
Short-Circuit
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 4
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
PDRV Output Block Output source current Output sink current Output ON resistor Output source current NDRV Output Block Output sink current Output ON resistor Isource Isink ROH ROL Isource Isink ROH ROL VIH VIL ICTL Duty≥95% PDRV=0V Duty≤5% PDRV=5V PDRV=-15mA PDRV=15mA Duty≥95% NDRV=0V Duty≤5% NDRV=5V NDRV=-15mA NDRV=15mA Active mode Standby mode CTL=5.0V 1.5 0 65 65 -130 100 18 16 -130 100 18 16 30 25 VCC 0.8 20 4.10 4.20 4.30 100 2.94 3.0 3.06 100 0.4 2.0 30 25 -80 -80 mA mA Ω Ω mA mA Ω Ω V V µA V mV V mV V µA
Control Block
CTL input voltage CTL input Current VCC reset ON voltage VCC reset hysteresis
VRSTON1 VCC rising VRSTON1 hys VCC falling VRSTON2 3V3 rising VRSTON2 hys 3V3 falling VOL ILeak IL =1mA
RESET Monitor Block
3V3 reset ON voltage 3V3 reset hysteresis Reset output voltage Reset leakage current
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 5
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Typical Application Circuit: 3V3 Output
L1: AT1368A: 22µH/0.77A/104mΩ TDK-SLF6028T-220MR77 AT1368B: 10µH/1A/74.5mΩ TDK-SLF6028T-100M1R0 R1: AT1368A: 100K AT1368B: 10K
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 6
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 7
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Typical Application Circuit: 2V5 Output
*1V8 Output: R4:9.8KΩ R5:38.7KΩ *Vin from 2.5V to 7V, disable SCP function
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 8
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Typical Application Circuit: Zeta converter 3V3 Output
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 9
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset CH1:Reset CH2:SS CH3:Vout CH4:Vin
Fig.1 Vout:3.3V/1A Vin:5V Start-Up Waveform
Fig.2 Vout:2.5V/1A Vin:3.1V Start-Up Waveform
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 10
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Package Outline 16-pin SSOP
SYMBOL A A1 A2 b C D ZD E E1 L e y θ
MILLIMETERS MIN TYP MAX 1.35 1.60 1.75 0.10 0.15 0.25 1.50 0.20 0.30 0.18 0.25 4.80 4.85 5.00 0.20 5.79 5.99 6.20 3.81 3.91 3.99 0.41 0.71 1.27 0.64 0.076 0° 8°
MIN 0.053 0.004 0.008 0.007 0.189 0.228 0.150 0.016 0°
INCHES TYP 0.063 0.006 0.191 0.008 0.236 0.154 0.028 0.025 -
MAX 0.069 0.010 0.059 0.012 0.010 0.197 0.244 0.157 0.050 0.003 8°
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 11
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset
Package Outline 16-pin TSSOP
SYMBOL A A1 A2 b C D E E1 L e y θ
MILLIMETERS MIN TYP MAX 1.05 1.10 1.20 0.05 0.10 0.15 1.00 1.05 0.20 0.25 0.28 0.127 4.90 5.075 5.10 6.20 6.40 6.60 4.30 4.40 4.50 0.50 0.60 0.70 0.65 0.076 0° 8°
MIN 0.041 0.002 0.008 0.193 0.244 0.170 0.020 0°
INCHES TYP 0.043 0.004 0.039 0.010 0.005 0.1998 0.252 0.173 0.024 0.026 -
MAX 0.047 0.006 0.041 0.011 0.200 0.260 0.177 0.028 0.003 8°
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 12
AT1368
1-Channel Synchronous Buck PWM Controller with Power Good Reset Reflow Condition (IR/Convection or VPR Reflow)
Reference JEDEC Standard J-STD-020A
Classification Reflow Profiles Convection or IR/Convction
Average Heating Rate(180°C to peak) 5°C/second max. 120 seconds max. Preheat Temperature(125±20°C) 10~150 seconds Temperature maintained above 180°C Time within 5°C of actual Peak 10~20 seconds Temperature Peak Temperature Range(Note 1) 219~225°C or 235~240°C Cooling Rate 6°C /second max. 6 minutes max. Time 25°C to Peak Temperature
VPR
10°C/second max.
60 seconds 219~225°C or 235~240°C 10°C/second max.
*1 The maximum peak temperatures for IR and VP reflow are depending on package dimensions.
Package Reflow Conditions Pkg. Thickness ≥2.5mm Pkg. Thickness