TS TS3410CX5 Schematic [ru]

SOT

-25

Name

Description

Power

-

off pin

GND

Ground pin

Switch output pin. Connect external inductor

V

CC

IC power supply pin

FB

Output Feedback pin

Pin

Definition

:

TS3410

1A / 1.4MHz Synchronous Buck Converter

1. EN

2. Ground

3. Switching Output

4. Input

5. Feedback

General Description

TS3410 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode
architecture. The device is available in an adjustable version. Supply current with no load is 250uA and drops to
<1uA in shutdown. The 2.5V to 6V input voltage range makes TS3410 ideally suited for single Li-Ion, two to four
AA battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in
portable systems. PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive
applications. Switching frequency is internally set at 1.4MHz, allowing the use of small surface mount inductors
and capacitors. The internal synchronous switch increases efficiency and decreases need of an external Schottky
diode. Low output voltages are easily supported with the 0.6V feedback reference voltage.

Features

● High Efficiency: Up to 96%

● 2.5V to 6V Input Voltage Range

● Output Voltage from 0.6V to VIN

● Short Circuit Protection (SCP)

● Build in Soft-Start Function

● 1.4MHz Constant Frequency Operation

● Up to 1A Output Current

● Low Quiescent Current: 250uA (Typ.)

● No Schottky Diode Required in Application

● ≤1uA Shutdown Current

● Current Mode Operation for Excellent Line and
Load Transient Response

Ordering Information

Part No. Package Packing

TS3410CX5 RF SOT-25 3Kpcs/ 7” Reel

Application Circuit

VIN=2.5V~6V

U1

VIN

SW

EN

C1

4.7u

GND

AX3513

FB

Application

● Cellular Phones

● Digital Still Cameras

● Portable Electronics

● USB Devices

Pin Description

EN

SW

H：normal operation
L：Step-down operation stopped
(All circuits deactivated)

here. Minimize trace area at this pin to
reduce EMI.

L1

2.7uH

R1

600K

C3

15p

V

=1.8V

OUT

C2
10u

V

= 0.6 * (1+R1/R2)

OUT

R2=100K~330K

1/10

R2

300K

Version: C08

TS3410

1A / 1.4MHz Synchronous Buck Converter

Absolute Maximum Rating

Characteristics Symbol Rating Unit

VIN Pin Voltage VIN Gnd - 0.3 to Gnd + 6.5 V
Feedback Pin Voltage VFB Gnd - 0.3 to VIN + 0.3 V
RUN Pin Voltage V
Switch Pin Voltage VSW Gnd - 0.3 to VIN + 0.3 V
Peak SW Sink & Source Current I
Power Dissipation PD (TJ-TA) / θJA mW
Storage Temperature Range TST -40 to +150
Operating Temperature Range TOP -40 to +85
Junction Temperature TJ +125
Thermal Resistance from Junction to case θJC 110
Thermal Resistance from Junction to ambient θJA 250

Note1: θJA is measured with the PCB copper area of approximately 1 in2(Multi-layer). that need connect to Gnd pin
of the TS3410.

Gnd - 0.3 to VIN + 0.3 V

RUN

1.4 A

PSW

o

C

o

C

o

C

o

C/W

o

C/W

Electrical Specifications

(Ta = 25oC, VIN=V

=3.6V unless otherwise noted)

RUN

Characteristics Symbol Conditions Min Typ Max Units

Feedback Voltage V

Quiescent Current I

FB

VFB=0.5V -- 250 350 uA

CCQ

-40°C≤TA≤ 85°C 0.582 0.6 0.618

Feedback Bias Current IFB VFB =0.65V -- -- ±30 nA

TA =25℃,I

Shutdown Supply Current
Maximum Output Current
Current Limit I
Line Regulation
Load Regulation
Oscillation Frequency F
R
R

of P-CH MOSFET

DS(ON)

of N-CH MOSFET

DS(ON)

Efficiency E
EN pin logic Input

Threshold Voltage

ISD V

I

OUT(MAX)

LIMIT

△V

OUT/VOUT

△V

OUT/VOUT

OSC

R

DSON

R

DSON

FFI

V

ENL

V

ENH

=0V -- 0.1 1 uA

RUN

VCC =3V, V

VCC =3V 1.2 1.4 -- A

VCC = 2.5V~5.5V -- 0.04 0.4 %
I

= 0.01 to 0.6A -- 0.5 -- %

OUT

SW pin 1.1 1.4 1.7 MHz

ISW = 500mA -- 0.3 0.4 Ω
Note 1 -- 0.25 0.35 Ω

V

OUT

=3.3V,I

-- -- 0.4

1.5 -- --.

=50mA

OUT

=1.8V 1 -- -- A

OUT

= 0.5A

OUT

0.588 0.6 0.612

-- 94 -- %

V

V

EN Pin Input Current IEN -- ±0.1 ±1 uA
Thermal shutdown TDS -- 140 -- °C

Thermal
shutdown Hysteresis

TSH -- 30 -- °C

Note 1: Guaranteed by Design
Note 2: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and

characterization.

2/10

Version: C08

1A / 1.4MHz Synchronous Buck Converter

Block Diagram

TS3410

VIN

FB

REF

0.6V

Soft-Star

+

-

-

+

Over-Temperature and
Short-Circuit Protection

OSC

Icomp

SLOPE

COMP

SET

RESET

PWM

LOGIC

Enable Logic

EN

+

Isense

AMP

-

NON-OVERLAP

CONTROL

+

Izero

-

COMP

SW

GND

Function Description

Operation

TS3410 is a monolithic switching mode step-down DC-DC converter. It utilizes internal MOSFETs to achieve high
efficiency and can generate very low output voltage by using internal reference at 0.6V. It operates at a fixed
switching frequency, and uses the slope compensated current mode architecture. This step-down DC-DC
Converter supplies minimum 1000mA output current at input voltage range from 2.5V to 5.5V.

Current Mode PWM Control

Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for
excellent load and line transient responses and protection of the internal main switch (P-Ch MOSFET) and
synchronous rectifier (N-CH MOSFET). During normal operation, the internal P-Ch MOSFET is turned on for a
certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the
peak inductor current is above the error voltage. The current comparator, ICOMP, limits the peak inductor current.
When the main switch is off, the synchronous rectifier will be turned on immediately and stay on until either the
inductor current starts to reverse, as indicated by the current reversal comparator, IZERO, or the beginning of the
next clock cycle..

3/10

Version: C08

Note: Part Type MH or M (www.we

-

online.com)

TS3410

1A / 1.4MHz Synchronous Buck Converter

Application Information

Setting the Output Voltage

Application circuit item shows the basic application circuit with TS3410 adjustable output version. The external
resistor sets the output voltage according to the following formula:

Inductor Selection

For most designs, the TS3410 operates with inductors of 2.2µH to 3.3µH. Low inductance values are physically
smaller but require faster switching, which results in some efficiency loss. The inductor value can be derived from
the following formula:

Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high
ripple currents. Choose inductor ripple current approximately 20% of the maximum load current 1A, ∆IL=200mA.

For output voltages above 2.0V, when light-load efficiency is important, the minimum recommended inductor is

2.7µH. For optimum voltage-positioning load transients, choose an inductor with DC series resistance in the 50mΩ
to 150mΩ range. For higher efficiency at heavy loads (above 200mA), or minimal load regulation (but some
transient overshoot), the resistance should be kept below 100mΩ. The DC current rating of the inductor should be
at least equal to the maximum load current plus half the ripple current to prevent core saturation (1000mA+100mA)

Table 1: Resistor Select for Output Voltage Setting

VOUT R2 R1

Table 2: Inductor Select for Output Voltage Setting (VIN=3.6V)

1.2V 300K 300K

1.5V 300K 450K

1.8V 300K 600K

2.5V 150K 470K

3.3V 120K 540K
5V 124K 910K

VOUT 1.2V 1.5V 1.8V 2.5V

Inductor 2.7uH 2.7uH 2.7uH 2.2uH

Part Number

WE-TPC

7440430027 7440430027 7440430027 7440430022

Input Capacitor Selection

The input capacitor reduces the surge current drawn from the input and switching 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 RMS current must
be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and
small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient.

Output Capacitor Selection

The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The
output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R
dielectrics are recommended due to their low ESR and high ripple current.

Compensation Capacitor Selection

The compensation capacitors for increasing phase margin provide additional stability. It is required and more than
15pF. Please refer to demo board schematic for design.

4/10

Version: C08