TS2507
0.5A / 330KHz PWM Buck Controller
SOP-8
Pin Definition: 1 . EN 5. FB 2 . C o mp 6 . Vs s 3 . Oc s e t 7. LX 4 . Vc c 5. Gate
General Description
The TS2507 integrates Pulse- Width-Modulation ( PW M) control circuit into a s ingle chip. These devise include a reference voltage source, oscillation circuit, error amplifier and etc. TS2507 pr ovides low-ripple power, high efficiency, and excellent transient characteris tics. The PW M control c ircuit is able to very the duty ratio linearly for m 0 up to 100%. This controller also contains an error amplifier circuit as well as a soft-s tart circuit that prevents over shoot at startup. An enable function, an over current protect function and shor t circuit protect func tion are built inside, and when OC P or SC P happens , the operation frequency will be r educed. Also, an internal compensation block is built in to minimum external component count. With the addition of an ex ternal P-channel Power MOS, a coil, capacitors, and a diode connec ted externally , these components can function as step-down switching regulators. They serve as ideal power supply units for portable devices w hen coupled with the SOP-8, providing such outstanding features as low current consumption. Since this converter can accommodate an input
Features
● ● ● ● ● ● ● ● ● ● Input Voltage: 3.6V~24V Output Voltage: 0.8V~Vcc Duty R atio: 0%~100% PW M Control Oscillation Frequency: 330kHz typ. Soft- Start (SS), Current Limit (CL) , Enable Func tion Thermal Shutdown Function Shor t Circuit Protec t ( SC P) External SW P-Channel MOSFET Low ESR Output Capac itor Application SOP-8 Pb-Free Package
Ordering Information
Part No.
TS2507C S R L
Package
SOP-8
Packi ng
2.5Kpcs / 13” Reel
Application
● ● Simple High-efficiency Step dow n Regulator On-Card Switching Regulators
Absolute Maximum Rating
Parameter
VCC Pin Voltage Feedback Pin Voltage ON/OFF Pin Voltage Switch Pin Voltage Power Dissipation Storage Temperature Range Operating Temperature Range Operating Supply Voltage Thermal R esistance from Junc tion to case Thermal R esistance from Junc tion to ambient
Symbol
VCC VFB VEN VSW PD TST TOP VOP θJ C θJ A 1/9
Rati ng
VSS - 0.3 to VSS + 26 VSS - 0.3 to VCC VSS - 0.3 to VCC + 0.3 VSS - 0.3 to VCC + 0.3 Inter nally limited - 40 t o + 150 - 20 t o + 125 +3.6 to +24 40 120
Unit
V V V V mW ℃ ℃ V ℃/ W ℃/ W Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Electrical Specifications (VIN=12V, Ta=25oC unless otherwise noted)
Parameter
Feedback Voltage Quiescent Current Feedback Bias Current Shutdown Supply Current OCSET pin bias current Line R egulation Load R egulation Oscillation Frequency EN Pin Logic input threshold voltage EN Pin Input Current Soft- Start Time LX Rise Time LX Fall Time Efficiency Thermal shutdown Temp
Symbol
VFB Iq IFB ISD IOCSET ∆VOUT/VOUT ∆VOUT/VOUT FOSC VSH VSL ISH ISL TSS TLXR TLXF EFFI TSD
Conditi ons
IOUT=0.1A VFB=1.2V force driver off IOUT=0.1A VEN =0V VCC = 5V~24V, IOUT=0.2A IOUT = 0.1 to 5A SW pin High (regulator ON) Low (regulator OFF) VEN=2.5V (ON) VEN=0.3V (OFF) CLX=1000pF CLX=1000pF VOUT = 5V IOUT = 2A IOUT = 3A
Mi n
0.784 ---95 --260 2.0 ---0.3 ------
Ty p
0.800 3 0.1 2 110 0.6 0.3 330 --20 - 10 4 45 45 92 91 125
Max
0.816 5 0.5 10 125 1.2 0.5 400 -0.8 --8 ------
Units
V mA uA uA uA % % KHz V uA uA ms nS % ℃
Block Diagram
Pin Assignment
Name
EN Comp OC S E T Vcc
Descripti on
Shutdown Control Input. H：nor mal operation ( Step-down) L：Shutdown mode Compensation pin Add an external res istor to set max sw itch output current. IC power supply pin
Name
Ga t e LX Vss FB
Descripti on
Gate drive for ex ternal P-channel MOSFET. LX is the current sense input. GND pin Feedback pin
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Application Circuit
A. Typical Application Circuit
B. MLC C (TS2507)
C. Standby C urrent ( IOUT=0A) < 4mA
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Function Descriptions
PW M Control The TS2507 integrates Pulse-Width- Modulation ( PW M) control circuit into a single chip. the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage pr oduced by the switching can easily be removed through a filter because the switching frequency remains cons tant. Therefore, these controllers prov ide a low-ripple power over broad ranges of input voltage and load current. RDS(ON) Current Limit ing The current limit threshold is setting by the external r esistor (R3) connec ting from VCC supply to OCSET pin. The internal 110uA sink current crossing the resis tor sets the voltage at pin of OC SET. When the PWM voltage is less than the voltage at OC SET, an over-current condition is triggered. Please refer to the formula for setting the cur rent limit value
(Nor mally, The ISW(MAX) setting more than IOUT 1A) Example: ISW=(110uA * 1.8k + 0.11) / 50mΩ ( TSM9435CS) = 6.16A Setting the Output Voltage Application circuit item shows the bas ic application c ircuit with TS2507 adjustable output version. The ex ternal resis tor sets the output voltage according to the follow ing equation:
Table 1: Resis tor select for output voltage setting VOU T R2 R1 1.3K 6.8K 5V 5.6K 30K 1.5K 4.7K 3.3V 5.6K 18K 2.2K 4.7K 2.5V 5.6K 12K 1.8V 1.2K 1.5K 1.5V 2.2K 2K 1.2V 2K 1K 1V 2K 0.5K Input C apacitor Selection The input capacitor reduces the sur ge current drawn from the input and sw itching noise from the device. The input capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum R MS current mus t be used. The capacitor voltage rating should be at least 1.5 times greater than the input voltage, and often much higher voltage ratings are needed to satis fy. Output Capacitor Selection The output capacitor is required to keep the output v oltage ripple small and to ensure regulation loop stability . The output capacitor must have low impedance at the switching frequency. A low ESR capacitor sized for maximum R MS current mus t be used. the low ESR requirements needed for low output r ipple voltage. The capacitor voltage rating should be at leas t 1.5 times greater than the input voltage, and often much higher voltage ratings are needed to satisfy.
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TS2507
0.5A / 330KHz PWM Buck Controller
Function Descriptions (Continue)
Inductor Select ion For most designs, Low inductance values are physic ally smaller but require faster switching, which results in some efficiency loss. The inductor value can be derived from the following equation:
Where is induc tor Ripple Current. Large value inductors lower ripple current and small value induc tors result in high ripple currents . Choose inductor ripple current approximately 15% of the maximum input current 3A, ∆IL=0.45A. Table 2 Inductor select for output voltage setting (TS2507 at VCC =12V) VOU T L1 Value 2.5V 15uH 3.3V 18uH 5V 22uH 3.3V(5A) 12uH 5V(5A) 15uH
The DC current rating of the induc tor should be at leas t equal to the maximum load current plus half the ripple current to pr event core saturation (3A+0.3A). Layout Guidance When laying out the PC board, the follow ing sugges tions should be taken to ensure proper operation of the TS2507. These items are also illus trated graphically in below. 1. The power traces , including the PMOS Drain & Sour ce trace, the Schottky and the C2 trace should be kept short, direc t and w ide to allow large current flow . 2. Connect the C5 to the VCC & EN pins of the TS2507 as closely as possible to get good power filter effec t. 3. Keep the switching node, away from the sensitive FB node. 4. C onnect ground side of the C2 & D 1 as closely as possible. 5. C onnect PMOS Source and R3 as closely as possible. 6. D o not trace signal line under inductor .
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Electrical Characteristics Curve
Fi gure 1. Feedback Voltage vs. Input Voltage
Fi gure 2. Quiescent Curr ent vs. Input Voltage
Fi gure 3. IOSET vs. Input Voltage
Fi gure 4. Frequency vs. Input Voltage
Fi gure 5. Feedback Voltage vs. Temper ature
Fi gure 6. Qui escent Current vs. Temper ature
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Electrical Characteristics Curve
Fi gure 7. IOCSET vs. Temper ature
Fi gure 8. Frequency vs. Temper ature
Fi gure 9. Efficiency vs. Output Curr ent
Fi gure 10. Effi ciency vs. Output Current
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
SOP-8 Mechanical Drawing
DIM A B C D F G K M P R
SOP-8 DIMEN SION MILLIMETER S INCH ES MIN MAX MIN MAX. 4.80 5.00 0.189 0.196 3.80 4.00 0.150 0.157 1.35 1.75 0.054 0.068 0.35 0.49 0.014 0.019 0.40 1.25 0.016 0.049 1.27BSC 0.05BSC 0.10 0.25 0.004 0.009 0º 7º 0º 7º 5.80 6.20 0.229 0.244 0.25 0.50 0.010 0.019
Marking Diagram
Y = Year Code M = Month C ode (A=Jan, B =Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep, J=Oc t, K=Nov , L=Dec) L = Lo t C ode
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Version: A07
TS2507
0.5A / 330KHz PWM Buck Controller
Notice
Specifications of the produc ts displayed herein are s ubject to change without notice. TSC or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Infor mation contained herein is intended to pr ovide a product description only. N o license, express or implied, to any intellectual proper ty 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 par ticular purpose, merchantability, or infringement of any patent, copyright, or other intellectual proper ty right. The products shown herein are not designed for use in medical, life-saving, or life-sus taining applications . C ustomers 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.
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