ANPEC APW7016 Service Manual

APW7016

Advanced PWM Power Controller

Features General Description

• Simple Single-Loop Control Design

−Voltage-Mode PWM Control

• Excell Output Voltage Regulation

−PWM Output : ±1% Over Temperautre

• Fast Transient Response

−High-Bandwidth Error Amplifier

−Full 0% to 100% Duty Ratio

• 3-Bit Digital-to-Analog Output Voltage Selection

• Over-Voltage and Over-Current Fault Monitors

• Small Converter Size

−200kHz

Free-Running Oscillator

−Programmable from 50KHz to 800KHz

Applications

High-Power 5V to 3.xV (or below) DC-DC Regu-

•

lators

• Low-Voltage Distributed Power Supplies

• VGA Card Power Regulation

The APW7016 provides a complete control and protection for a DC-DC converter optimized for high performance microprocessor applications. It is designed to drive two N-Channel MOSFETs in a synchronousrectified buck topology. The APW7016 integrates output voltage control , monitoring and protection functions into a single Package. The APW7016 includes a 3-bit digital-to-analog converter (DAC) that provides a easily adjustable and precisely output voltage from 1.3VDC to 1.65V

0.05V steps. Any selected output voltage can be maintained within ±1% accuracy over temperature and line voltage variations. With a 200kHz free-running triangle-wave oscillator and a error amplifier featuring a 15MHz unity-gain bandwidth and 6V/us slew rate inside the chip , APW7016 can implement a simple , single feedback loop , voltage-mode control topology with high transient performance. The APW7016 also features with multiple protections against over-current and over-voltage conditions by inhibiting PWM operation. The APW7016 uses the R

of the upper MOSFET as the current sensing

DS(ON)

element which eliminates the demend for an extra component. The APW7016 also monitors the output voltage using a comparator with hysteresis that tracks the DAC output.

Pin Description

VSEN

OCSET

VID0

VID2

COMP

ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders.

1 2 3 4 5 6 7 8

16 15 14

13 12 11 10

RT VCC LGATE

PGND BOOTVID1 UGATE

PHASE

GND

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APW7016

Ordering and Marking Information

APW 7016

APM 7016 K/N :

Block Diagram

SEN

VID0 VID1 VID2

COMP

TTL D/A

CONVERER

(DAC)

APM 7017 XXXXX

DETN (Power on Reset)

DAC OUT

Lead Free Code Hand ling Code Temp. Range Package Code

115%

ERRAMP

DETN (Power on Reset)

OVP

SOFT

START

OSC

Package Code K : SOP - 16 N : SSOP - 16 Temp. Range C : 0 to 7 0 C Hand ling Code T U : T u b e T R : T a p e & R e e l Lead Free Code L : Lead Free Device Blank : Original Device

XXXXX - Date Code

PHASE

CP4

+ +

DETN, OC

VCC

200

CP1

Power on

Reset

UGATE

DRIVER

DETN (Power on Reset)

OCSET

BOOT

UGATE

PHASE

LGATE

PGND

GND

Absolute Maximum Ratings

Symbol Parameter Rating Unit

BOOT

STG

Supply Voltage 15 V Boot Voltage 15 V Input , Output or I/O Voltage GND - 0.3 V to VCC + 0.3 V

Operating Ambient Temperature Range 0 to 70 Junction Temperature Range 0 to 150 Storage Temperature Range -65 to +150 Soldering Temperature 300,10 seconds

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APW7016

Thermal Characteristics

Symbol Parameter Value Unit

Electrical Characteristics

Recommended operating conditions , unless otherwise noted

Thermal Resistance in Free Air

SOP , SSOP SOP (with 3in

of Copper)

110

C/W

Symbol Parameter Test Conditions

Supply Current

Nominal Supply UGATE and LGAT E open 3 mA

APW7016

Min. Typ. Max.

Power-on Reset

Rising VCC Threshold Vocset=4.5V 10.7 V Falling VCC Threshold Vocset=4.5V 8.2 V

Oscillator

Free Running Frequency RT= Open 185 200 215 kHz

∆

Ramp Amplitude RT= Open 2 V

OSC

Reference and DAC

DAC(VID0-VID2) Input Low Voltage 0.8 V DAC(VID0-VID2) Input High Voltage 3.0 V DACOUT Voltage accuracy -1.0 +1.0 %

Error Amplifier

DC Gain 88 dB

GBW Gain-Bandwidth Product 15 MHz

SR Slew Rate COMP=20pF 6

PWM Controller Gate Driver

R R R R

UGATE

LGATE

UGATE Source VCC=12V , V UGATE Sink V

UGATE-PHASE

LGATE Source VCC=12V , V LGATE Sink V

=1V 3.5 6.5

LGATE

=6V 350 500 mA

UGATE

=1V 5.5 10

=1V 350 450 mA

LGATE

Protection

OCSET

Over-Voltage T rip (V OCSET Current Source V Soft Start Current 10

/DACOUT) 115 120 %

SEN

OCSET

=4.5V

170 200 230

Unit

P-P

V/µs

Ω

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APW7016

Pin Function Description

VSEN (pin 1)

Connect this pin to the converter’s voltage output. The OVP comparator circuits monitor output voltage status and act over voltage protection by using this signal.

OCSET(pin 2)

Connect a resistor(R of the upper MOSFET. An internal 200µA current source (I resistance (R

OCS

), R

OCSET

DS(ON)

(OC) trip point according to the following equation :

* R

PEAK

OCSET

DS(ON)

An over-current trip resets the soft-start function.

SS (Pin 3)

Connect a capacitor from this pin to ground. This capacitor, along with an internal 10µA current source, sets the soft-start interval of the converter.

) from this pin to the drain

OCSET

, and the upper MOSFET’s on-

) set the converter over-current

OCSET

PHASE (pin 10)

Connect the PHASE pin to the source of the upper MOSFET. This pin is used to monitor the voltage drop across the upper MOSFET for over-current protection.

UGATE (pin 11)

Connect UGATE to the upper MOSFET gate. This pin enables the gate drive signal to drive the upper MOSFET .

BOOT (pin 12)

BOOT pin provides bias voltage to the upper MOSFET gate driver. A bootstrap circuit could be used to pump a BOOT voltage for enforcing the driving capability of the gate driver and improving the performance of the upper MOSFET.

PGND(pin 13)

PGND pin provides the power ground connection. Connect this pin to the source of the lower MOSFET.

VID0-2 (Pins 4-6)

VID0-2 are the input pins to the 3-bit DAC. The states of these three pins decide the internal voltage reference (DACOUT). The level of DACOUT sets the converter output voltage and also sets the OVP thresholds. Table 1 specifies DACOUT for the 8 combinations of DAC inputs.

COMP (pin 7) and FB (pin 8)

COMP and FB are the accessiable pins of the error amplifier. FB pin is the inverting input of the error amplifier and COMP pin is output of the error amplifier. These pins provide the compensation for the voltage-control feedback loop of the converter.

GND (Pin 9)

GND is signal ground of the IC. All voltage levels are measured with respect to this pin.

LGATE (pin 14)

Connect LGATE to the lower MOSFET gate. This pin enables the gate drive signal to drive the lower MOSFET.

VCC (pin 15)

Connect VCC to 12V voltage supply. This pin supplies the bias for the chip.

RT (pin 16)

RT pin provides oscillator switching frequency adujstment. By connecting a resistor (RT) from this pin to GND, the nominal 200kHz switching frequency is increased. Conversely. connecting a pull-up resistor (RT) from this pin to VCC reduces the switching frequency.

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