Innuovo XN1049DP, XN1049SP, XN1049TP Schematic [ru]

XN1049 Switch Power Supply PWM Controller

XN1049 Switch Power Supply PWM Controller

General Description

XN1049 which is optimized for high performance is a

highly integrated current mode PWM control IC. It is

applied for switch power of the small-sized and

medium-sized for example the power adaptor. For

lower the standby power and higher RoHS compliant,

the IC has the Burst Mode function and very low

startup current and working current. At the condition

of no load or light load, the IC operates in extended

‘burst mode’ to minimize switching loss by lower the

switching frequency. The low startup current and low

operating current contribute to a reliable power on

startup design with XN1049. A large value resistor

could thus be used in the startup circuit to minimize

the power consumption and improve the efficiency of

the power convent.

noise is eliminated during operation. The IC can be

used as the best alternative products of the linear

power supply or the RCC-mode power to improve the

whole performance of the switch power system and

lower the cost. XN1049 is offered in SOT23-6, SOP-8

and DIP-8 packages.

Features

 Extended burst mode control for improving

efficiency and minimum standby power

 Low startup current(4uA)
 Low operation current(1.4mA)
 Leading edge blanking was built in
 Synchronous slope compensation was built in

The internal synchronous slope compensation circuit

improves system large signal stability and reduces the

possible subharmonic oscillation at high PWM duty

cycle output. Leading-edge blanking on current

sense(CS) input removes the signal glitch due to

snubber circuit diode reverse recovery and thus

greatly reduces the external component count and

system cost in the design. XN1049 offers complete

protection coverage with automatic self-recovery

feature including over current protection cycle by

cycle (OCP), over load protection (OLP), under

voltage lockout (UVLO). The gate-driven output is

clamped to maximum 18V to protect the external

MOSFET. Excellent EMI performance is achieved by

using the frequency jitter and the soft-switching at the

totem-pole-gate-drive output. The tone energy at

below 20KHZ is minimized in the design and audio

 Current mode operates
 External programmable PWM switching

frequency

 Over current protection cycle by cycle(OCP)
 Good protection coverage with auto self-

recovery

 VDD over voltage clamp and under voltage

lockout with hysteresis (UVLO)

 Maximum gate-drive output clamped voltage

(18V)

 Frequency jitter
 Constant limited output power
 Over load protection(OLP)
 Free audio noise operation

◎Xi’an Innuovo Microelectronics Co., Ltd. June, 2008
DS.XN1049V1.0

Page 1

Applications

XN1049 Switch Power Supply PWM Controller

Universal switch power supply and offline AC/DC

flyback converter:

 Battery Charger

Typical Application Circuit

 Power Adaptor
 Set-Top Box Power Supplies

 Open-frame SMPS

Pin Definition and Device Marking

GND

FB

RI

VDD

SENSE

1

2

3

1

2

3

4

SOT23-6

DIP8

SOP8

6

5

4

8

7

6

5

GATE

VDD

SENSE

GNDGATE

FB

NCNC

RI

49: XN1049
Y: Year Code
WW：Week Code

X: D = DIP8 ， S = SOP8
P: P = Pb-free package
Y: Year Code (0-9)
WW: Week Code (1-52)
X: Area Code
V: Internal Version Code (1-9)

◎Xi’an Innuovo Microelectronics Co., Ltd. June, 2008
DS.XN1049V1.0

Page 2

XN1049 Switch Power Supply PWM Controller

Ordering Information

Package IC Marking Information Purchasing Device Name

8-Pin DIP8, Pb-free XN1049DP XN1049DP

8-Pin SOP8, Pb-free XN1049SP XN1049SP

6-Pin SOT23-6, Pb-free 49 YWW XN1049TP（SOT23-6）

Pin Function Description

Pin Name Pin No.

DIP8/SOP8

GND 8 / 1 Ground Ground

FB 7 / 2

RI 5 / 3

NC 3 Floating Floating

NC 6 Floating Floating

SENSE 4 / 4

VDD 2 / 5 Power DC power supply pin

GATE 1 / 6 Output Totem-pole gate drive output for the power MOSFET

Pin T ype Function Description

Feedback

Input

Frequency

Setting

Current

Monitoring

Feedback input pin. The PWM duty cycle is determined by voltage

into this pin and the current-sense signal at Pin 4

Internal oscillator frequency setting pin. A resistor which is

connected between RI and GND sets the PWM frequency

Current detection flyback input pin for estimating reaching the limit

◎Xi’an Innuovo Microelectronics Co., Ltd. June, 2008
DS.XN1049V1.0

Page 3