TS1935 1.6MHz Boost Converter with 30V Internal FET Switch SOT-25 Pin Definition: 1. SW 2. Ground 3. FB 4. EN 5. Input General Description Typical Application Circuit The TS1935 switching regulator is current –mode boost converters operating at fixed frequency of 1.6MHz. The use of SOT-25 made possible by the minimal power loss of the internal 1.6A switch, and use of small inductor and capacitors result in the industry’s highest power density. The 30V internal switch makes these solutions perfect for boosting to voltages up to 30V. These parts have a logic-level shutdown pin that can be used to reduce quiescent current and extend battery life. Protection is provided through cycle-by-cycle current limiting and thermal shutdown. Internal compensation simplifies and reduces component count. Features ● 30V DMOS FET Switch ● 2.7V to 5.5V Input Range ● 1.6MHz Switching Frequency ● Low R DSON DMOS FET ● Switch Current up to 1.6A ● Low Shutdown Current <1uA ● Use Tiny Capacitors and Inductor ● Cycle-by-Cycle Current Limiting Application ● White LED Current Source ● Digital Still Cameras ● Portable Electronics ● PDA’s and Palm-Top Computers ● Local Boost Regulator Ordering Information Part No. Package Packing TS1935CX5 RF SOT-25 3Kpcs / 7” Reel 1/8 Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Absolute Maximum Rating Parameter Symbol Limit Unit Input Voltage VIN 6 V VEN, VFB VIN V VSW 30 EN, VFB Voltage SW Voltage Ambient Temperature Range TA Junction Temperature Range TJ Storage Temperature Range TSTG V -40 to +85 o -40 to +125 o -65 to +150 o C C C ESD Classification B* Note: Stress above the listed absolute maximum rating may cause permanent damage to the device * HBM B: 2000~3999V Thermal Information Parameter Symbol Thermal Resistance* (Junction to Case) Maximum 81 260 400 150 350 ӨJC Thermal Resistance* (Junction to Ambient) ӨJA Internal Power Dissipation PD Maximum Junction Temperature Solder Iron (10 Sec)** * Measure ӨJC on center of molding compound if IC has no tab. ** MIL-STD-202G210F Unit o C/W o C/W mW o C o C Pin Description Pin Number Pin Name Description Power Switch Input. 1 SW 2 GND This is the drain of the internal NMOS power switch. Minimize the metal trace area connected to this pin to minimize EMI. Ground. Tie directly to ground plan. Output voltage feedback input. Set the output voltage by selecting values for R1 and R2 using: 3 FB Connect the ground of the feedback network to a GND plane. Enable, active high. 4 EN The enable pin is an active high control. Tie this pin above 2V to enable the device. Tie this pin below 0.4V to turn off the device. 5 IN Analog and Power input. Input Supply Pin. Place bypass capacitor as close to Vin as possible. 2/8 Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Electrical Specifications (Ta = 25 oC, VIN=5V, EN=VIN, IL=0A unless otherwise noted) Parameter Symbol Input Voltage VIN Feedback Pin Bias Current IFB VFB =1.23V Regulated Feedback Voltage VFB VIN =3V FB Voltage Line Regulation Test Condition Min Typ Max Unit 2.5 -- 5.5 V -- 60 500 nA 1.205 1.23 1.255 V -- 0.02 -- %/V VIN =2.7V 5.4 7 -- VIN =3.3V 8 10 -- VIN =5V 13 17 -- VIN =2.7V 3.75 5 -- VIN =3.3V 5 6.5 -- VIN =5V 8.75 11 -- 1.5 1.8 -- 1.2 -- -- -- 0.4 0.6 Ta = -40~ +85 C -- -- 0.7 VIN =3.3V, -- 0.5 0.7 -- -- 0.8 -- 0.1 1 -- 2 -- -- -- 3 -- 400 -- -- -- 500 EN = 0 -- 0 -- EN = 5V -- 0 2 ∆VFB /∆VIN 2.7V ≤ VIN ≤ 5.5V RL= 43Ω Minimum Output Voltage Under Load VOUT (MIN) RL= 43Ω o Switch Current Limit ICL Ta = 25 C o Ta = -40~ +85 C VIN =5V, o Switch ON Resistance RDSON o Ta = -40~ +85 C Shutdown Current ISD VEN =0V o Ta = 25 C FB = 1.15V VIN =5V, (Switching) Quiescent Current o Ta = -40~ +85 C IQ o Ta = 25 C FB = 1.3V VIN =5V, (No Switching) o Ta = -40~ +85 C V A A uA mA uA EN Pin Bias Current IEN Switching Frequency fSW Ta = -40~ +85 C 1 1.6 1.85 MHz Switching Leakage Current ISW VEN =0V Maximum Duty Cycle EN Input Threshold (High) (Shutdown) EN Input Threshold (Low) (Enable the device) o uA -- 0.1 2 uA o 86 93 -- % o -- -- 1.4 DMAX Ta = -40~ +85 C VEH Ta = -40~ +85 C V VEL o Ta = -40~ +85 C 3/8 2 -- -- Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Function Block Diagram Pin Description The TS1935 is a switching converter IC that operates at a fixed frequency (1.6MHz) for fast transient response over a wide input voltage range and incorporates pulse-by-pulse current limiting protection. Because this is current mode control, a 33mΩ sense resistor in series with the switch FET is used to provide a voltage (which is proportional to the FET current) to both the input of the pulse width modulation (PWM) comparator and the current limit amplifier. At the beginning of each cycle, the S-R lath turns on the FET. As the current through the FET increases, a voltage (proportional to this current) is summed with the ramp coming from the ramp generator and then fed into the input of the PWM comparator. When this voltage exceeds the voltage on the other input (coming from the Gm amplifier), the latch resets and turns the FET off. Since the signal coming from the Gm amplifier is derived from the feedback (which samples the voltage at the output), the action of the PWM comparator constantly sets the correct peak current through the FET to keep the output voltage in regulation. Q1 & Q2 align with R3 – R6 form a bandgap voltage reference used by the IC to hold the output in regulation. The currents flowing through Q1 & Q2 will be equal, and the feedback loop will adjust the regulated output to maintain this . Because of this, the regulated output is always maintained at a voltage level equal to the voltage at the FB node “multiplied up” by the ratio of the output resistive divider. The current limit comparator feeds directly into the flip-flop that derives the switch FET. If the FET current reaches the limit threshold, the FET is turned off and the cycle terminates the pulse regardless of the status of the output of the PWM comparator. 4/8 Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Electrical Characteristics Curve Figure 1. IQ Vin (Active) vs. Temperature Figure 2. IQ Vin (Idle) vs. Temperature Figure 3. Oscillator Frequency vs. Temperature Figure 4. Max. Duty Cycle vs. Temperature Figure 5. Feedback Bias Current vs. Temperature Figure 6. Efficiency vs. Load Current 5/8 Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Electrical Characteristics Curve Figure 7. Efficiency vs. Load Current Figure 8. Efficiency vs. Load Current Figure 9. Efficiency vs. Load Current Figure 10. Efficiency vs. Load Current Figure 11. RDS(ON) vs. Temperature Figure 12. RDS(ON) vs. VIN 6/8 Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch SOT-25 Mechanical Drawing DIM A+A1 B C D E E H L Ө1 S1 7/8 SOT-25 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX. 0.09 1.25 0.0354 0.0492 0.30 0.50 0.0118 0.0197 0.09 0.25 0.0035 0.0098 2.70 3.10 0.1063 0.1220 1.40 1.80 0.0551 0.0709 1.90 BSC 0.0748 BSC 2.40 3.00 0.09449 0.1181 0.35 BSC 0.0138 BSC 0º 10º 0º 10º 0.95 BSC 0.0374 BSC Version: A07 TS1935 1.6MHz Boost Converter with 30V Internal FET Switch Notice Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, to any intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of sale for such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify TSC for any damages resulting from such improper use or sale. 8/8 Version: A07