Datasheet AN8016NSH Datasheet (Panasonic)

Voltage Regulators

AN8016NSH

Single-channel 1.8-volt step-up DC-DC converter control IC

■ Overview

Unit: mm

The AN8016NSH is a single-channel PWM DC-DC
converter control IC that supports low-voltage operation.
This IC allows a stepped-up voltage output to be pro­vided with a minimal number of external components. It
features a low minimum operating voltage of 1.8 V, and

1

5

0.5

10

0.2±0.1

6

due to being provided in a 10-pin surface mount package
with a 0.5 mm lead pitch, is optimal for use in miniature

+0.1

–0.05

0.15

0.625±0.100.625±0.10

1.5±0.2

high-efficiency power supplies for portable equipment.

■ Features

•

Wide operating supply voltage range: 1.8 V to 14 V

•

High-precision reference voltage circuit: 1.27 V (allow-

0.1±0.1

0.5±0.2

4.3±0.30

6.3±0.30

ance: ± 3%)

•

Supports control over a wide output frequency range:

SSOP010-P-0225

20 kHz to 1 MHz

•

Provides a fixed output current with minimal supply voltage fluctuations by using an external resistor to set the output

current with a totem pole structure in the output block.

•

Large maximum output current of ± 50 mA

•

Timer latch short-circuit protection circuit (charge current: 1.3 µA typical)

•

Low input voltage malfunction prevention circuit (U.V.L.O.) (circuit operation start voltage: 1.6 V typical)

•

On/off control function (active-high, standby current: 5 µA maximum)

•

Fixed maximum duty ratio with small sample-to-sample variations (80% ± 5%)

•

Adjustable soft start time provided by using separate DTC and S.C.P. pins.

•

Adopts a 0.5 mm lead pitch 10 pin SO flat package (SSONF-10D)

•

Adopts techniques for reducing noise, increasing the light load efficiency, and suppressing the maximum base current

when turning on the npn transistor used as the external switching element.

3.0±0.30

■ Applications

•

LCD displays, digital still cameras, PDAs

1

AN8016NSH Voltage Regulators

■ Block Diagram

CC

Off

FB

IN−

Active-high

4

10

Error amp.

1

Low level detector
comp.

1.27 V

On/off
control

1.27 V

S.C.P.
comp.

Reference

voltage supply

1.27 V

SS pin

V

CC

1 µA

Low level

clamp

0.23 V

V

5

U.V.L.O.

High level detector comp.

1.27 V

2

OSC

9

Triangular wave

generator

Latch

R
S

0.6 V

Q

Unlatch comp.

0.7 V

0.2 V

0.23 V

PWM

V

Low level

clamp

3

CC

5 µA

V

CC

30 kΩ

8

6

7

RB

Out

GND

S.C.P.

■ Pin Descriptions

Pin No. Symbol Description

1IN− Error amplifier inverting input
2 S.C.P. Time constant capacitor connection for short-circuit protection
3 SS Soft-start time-constant capacitor connection
4 Off On/off control
5VCCSupply voltage
6 Out Push-pull output
7 GND Ground
8 RB Output-current setting resistor connection pin
9 OSC Oscillator circuit timing resistor/capacitor connection pin

10 FB Error amplifier output

SS

3

Voltage Regulators AN8016NSH

■ Absolute Maximum Ratings

Parameter Symbol Rating Unit

Supply voltage V
Off pin allowable application voltage
IN− pin allowable application voltage
Out pin allowable application voltage
Supply current I
Output source current I
Output sink current I
Power dissipation

*

Operating temperature T
Storage temperature T

Note) 1. Currents or voltages may not be applied to any pins not stipulated above. For circuit currents, a positive (+) value indicates

current flowing into the IC, and a negative (−) value indicates current flowing out of the IC.

2. Items other than the storage temperature, operating temperature, and power dissipation are all stipulated at Ta = 25°C.

3. *: Ta = 85°C. For the independent IC without a heat sink. Note that the relationship between IC power dissipation and
the ambient temperature must follow the derating curve.

CC

V

OFF

V

IN−

V

OUT

CC

SO(OUT)

SI(OUT)

P

D

opr

stg

15 V
15 V

V

CC

V

15 V

 mA

−50 mA
+50 mA

115 mW

−30 to +85 °C

−55 to +150 °C

■ Recommended Operating Range

Parameter Symbol Conditions Unit

Supply voltage V
Off control pin voltage V
Output source current I
Output sink current I
Timing resistance R
Timing capacitance C
Oscillator frequency f
Short-circuit protection time C

constant setting capacitance
Output current setting resistance R

CC

OFF

SO(OUT)

SI(OUT)

OUT

SCP

1.8 to 14 V
0 to 14 V

−40 (min.) mA

40 (max.) mA

T

T

3 to 30 kΩ

100 to 10 000 pF

20 to 1 000 kHz

1 000 (min.) pF

B

0 to 10k Ω

3

AN8016NSH Voltage Regulators

■ Electrical Characteristics at VCC = 2.4 V, Ta = 25°C

Parameter Symbol Conditions Min Typ Max Unit

U.V.L.O. block

Circuit operation start voltage V

UON

Error amplifier block

Input threshold voltage V
Line regulation with input fluctuation

V
Input bias current I
High-level output voltage V
Low-level output voltage V

PWM comparator block

Output source current I

Output block

Oscillator frequency f

OUT

Maximum duty Du
High-level output voltage V
Low-level output voltage V
Output source current I
Output sink current I

SO(OUT)VO

SI(OUT)VO

Pull-down resistor R

Unlatch circuit block

Input threshold voltage V

THUL

Short-circuit protection circuit block

Input threshold voltage V
Input standby voltage V

THPC

STBY

Input latch voltage V
Charge current I

CHG

On/off control block

Input threshold voltage V
Off mode SS pin voltage V
Off mode S.C.P. pin voltage V

ON(TH)

OFF(SS)

OFF(SCP)

Whole device

Average consumption current I
Latch mode consumption current I
Standby mode current I

CC(AV)

CC(LA)RB

CC(SB)

Voltage follower 1.23 1.27 1.31 V

TH

VCC = 1.8 V to 14 V  1.0 10 mV

dV

B

EH

EL

VSS = 0.5 V −3.5 −5 −6.5 µA

SS

RT = 12 kΩ, CT = 330 pF 170 190 2 10 kHz

max

IO = −15 mA, RB = 390 Ω 1.4  V

OH

IO = 10 mA, RB = 390 Ω0.2 V

OL

= 0.9 V, RB = 390 Ω−45 −32 −20 mA
= 0.3 V, RB = 390 Ω 20 mA

O

IN

V

= 0.5 V −1.65 −1.3 − 0.95 µA

SCP

RB = 390 Ω, Duty = 50%  3.4 5.0 mA

= 390 Ω1.8 2.4 mA

1.45 1.6 1.75 V

 0.2 1.0 µA

1.85 2.0 2.15 V

0.2 V

75 80 85 %

20 30 40 kΩ

0.13 0.20 0.27 V

1.17 1.27 1.37 V

 60 120 mV
 40 120 mV

0.8 1.0 1.3 V

0.13  0.27 V

0.13  0.27 V

 5 µA

5

Voltage Regulators AN8016NSH

■ Electrical Characteristics at VCC = 2.4 V, Ta = 25°C (continued)

•

Design reference data

Note) The characteristics listed below are theoretical values based on the IC design and are not guaranteed.

Parameter Symbol Conditions Min Typ Max Unit

U.V.L.O. block

Reset voltage V

Error amplifier block

VTH temperature characteristics V
Output source current I
Output sink current I

THdT

SO(FB)

SI(FB)

Open-loop gain A

PWM comparator block

SS pin voltage V

Output block

RB pin voltage V
Oscillator frequency supply f

voltage characteristics
Oscillator frequency temperature f

characteristics

Short-circuit protection circuit block

Comparator threshold voltage V

On/off control block

On/Off pin current I

OFF

R

Ta = −30°C to +85°C − 0.5 + 0.5 %
VFB = 0.5 V −40 µA
VFB = 0.5 V 2 mA

V

SS

RB = 390 Ω 0.13 V

B

VCC = 1.8 V to 14 V −1 +1%

dV

Ta = −30°C to 85°C −3 +3%

dT

THL

V

= 1.5 V 23 µA

OFF

0.8 V

80 dB

1.22 V

1.27 V

5

AN8016NSH Voltage Regulators

■ Terminal Equivalent Circuits

Pin No. Equivalent Circuit Description I/O

1IN−:I

V

CC

Error amplifier inverting input.

1

300 Ω

1.26 V

2 S.C.P.: O

2

0.23 V
3 kΩ

3 kΩ

V

CC

Latch

S

R

1.27 V

0.23 V

Low level detection comp.

Q

Output

cutoff

To the
on/off

control

circuit

Connection for the capacitor that sets the
timer latch short-circuit protection circuit time
constant. Use a capacitor with a value of
1 000 pF or higher.
The charge current I

is 1.3 µA (typical).

CHG

However, the capacitor is charged with a time
constant determined by 0.23 V and a resistance
of 6 kΩ until the pin voltage reaches 0.23 V.

3 SS: I

V

CC

Connection pin for the capacitor that determines
the PWM output soft start period. Note that the

0.23 V
3 kΩ

3 kΩ

3

PWM

C

T

Unlatch comp.

0.23 V

To the

on/off

control

circuit

S.C.P. pin

the short-circuit protection circuit does not
supply charge current to S.C.P. pin until this pin
voltage reaches about 0.2 V.
The source current I

is 5 µA (typical).

SS

However, the capacitor is charged with a time
constant determined by 0.23 V and a resistor of
6 kΩ until the pin voltage reaches 0.23 V.

4 Off: I

Internal

circuit

30 kΩ

start/stop

4

60 kΩ

This pin controls the on/off for the IC.
High-level input: normal operation
(V

> 1.3 V)

OFF

Low-level input: standby mode
(V

< 0.8 V)

OFF

In the standby state, the total IC current
consumption is decreased to 5 µA or under.

5

5

VCC: 
Power supply connection.
Provide an operating supply voltage of 1.8 V

to 14 V.

7

Voltage Regulators AN8016NSH

■ Terminal Equivalent Circuits (continued)

Pin No. Equivalent Circuit Description I/O

6 Out: O

7 GND: 

7

8 RB: I

V

CC

R1

8

I

O(SO)

V

CC

RB

30 kΩ

This is a push-pull output.
The absolute maximum rating for the output
current is ±50 mA. A constant-current output
with excellent line regulation and minimal

6

sample-to-sample variations can be acquired by
connected an external resistor to the RB pin.

IC ground.

Connection for the resistor that sets the output
current.
Use a resistor in the range 0 to 10 kΩ. Note that
the internal resistor R1 has a value of 1.0 kΩ.

Out

Thus the pin voltage will be 0.13 V when R

is

B

390 Ω.

9 OSC: O

10

V

CC

V

CC

Latch

S

Q

R

0.23 V

9

Connection for the capacitor and resistor that
determines the oscillator frequency. Use a
capacitor in the range 100 pF to 10 000 pF
and a resistor in the range 3 kΩ to 30 kΩ.
Use an oscillator frequency in the range
20 kHz to 1 MHz.

FB: O
Error amplifier output.

40 µA

C

PWM

A source current is about −40 µA and a sink
current is about 2 mA.
Correct the gain and the phase frequency

2 mA

characteristics by inserting a capacitor and
a resistor between this pin and IN− pin.

10

7

AN8016NSH Voltage Regulators

■ Usage Notes

•

Notes on IC power dissipation

Since the power dissipation in this IC increases proportionally with the supply voltage, applications must be careful

to operate so that the actual power dissipation does not exceed the power dissipation.

Since the output current set by the application circuit flows in the IC during the period corresponding to the output

on duty factor (Du, where Du

is 0.85), the IC power dissipation P is given by the following formula.

max

P = (V

CC

− V

BEQ1

) × I

× Du + VCC × ICC < P

OUT

D

■ Application Notes

[1] Power dissipation for the SSOP010-P-0225 package

PD  T

a

400
386

Glass epoxy printed

300
287

(mW)

D

200

154

115

Power dissipation P

100

circuit board
(50 × 50 × t0.8 mm

= 259°C/W

R

th(j−a)

Independent IC
without a heat sink

R

= 348°C/W

th(j−a)

3

)

0

0 25 50 75 85 100 125 150

Ambient temperature Ta (°C)

9

Voltage Regulators AN8016NSH

■ Application Notes (continued)

[2] Main characteristics

Timing capacitance  Oscillator frequency Maximum duty  Oscillator frequency

1 000

RT = 3 kΩ

RT = 6.2 kΩ

100

Oscillator frequency (kHz)

10

RT = 12 kΩ

RT = 30 kΩ

100 1 000 10 000

Timing capacitance (pF)

95

90

85

RT = 12 kΩ

80

Maximum duty (%)

75

70

10 100 1 000

RT = 30 kΩ

RT = 3 kΩ

RT = 6.2 kΩ

Oscillator frequency (kHz)

Error amplifier VTH temperature characteristics Oscillator frequency temperature characteristics

1.28

1.278

1.276

192

190

188

186

Voltage (V)

1.274

1.272

−30 −10 90

10 30 50 70

Ambient temperature Ta (°C)

Maximum duty temperature characteristics

81

80

79

78

Maximum duty (%)

77

76

−30 −10 90

10 30 50 70

Ambient temperature Ta (°C)

184

Oscillator frequency (kHz)

182

180

−30 −10 90

10 30 50 70

Ambient temperature Ta (°C)

9

AN8016NSH Voltage Regulators

■ Application Notes (continued)

[3] Timing charts (internal waveforms)

High

Off pin voltage

Power on

Supply voltage (V

Triangular wave (CT)

CC

)

Error amplifier output (FB)

S.C.P. pin voltage

SS pin voltage

Low

2.4 V

2.0 V

1.27 V

1.22 V

0.7 V

0.6 V

0.4 V

0.2 V

High

Out pin waveform

Short-circuit protection
comparator threshold level

Dead time voltage (VDT)

Error amplifier output (FB)

Triangular wave (CT)

Out pin waveform

S.C.P. pin voltage
Short-circuit protection

comparator output

Soft start operation

Figure 1. PWM comparator operating waveforms

Maximum duty: 80%

Low

2.0 V

1.27 V

0.6 V

High

Low

1.27 V

0.06 V

t

PE

High

Low

11

Figure 2. Short-circuit protection operating waveforms

Voltage Regulators AN8016NSH

■ Application Notes (continued)

[4] Functional descriptions

1. Reference voltage block
This circuit is composed of a band gap circuit, and outputs a 1.26-volt temperature compensated reference

voltage. This reference voltage is stabilized when the supply voltage is 1.8 V or higher.

2. Triangular wave generator
This circuit generates a triangular wave like

sawtooth with a peak of 0.75 V and a trough of 0.2
V using a capacitor (for the time constant) and resis­tor connected to the OSC pin (pin 9). The oscillator
frequency can be set to any value by selecting appro­priate values for the external capacitor and resistor,
C

and RT. This oscillator can provide a frequency in

T

the range 20 kHz to 1 MHz. The triangular wave sig­nal is provided to the inverting input of the PWM
comparator internally to the IC. Use the formulas
below for rough calculation of the oscillator fre­quency.

t

1

t

2

DischargeRapid

charge

T

Figure 1. Triangular oscillator waveform

V

V

OSCH

OSCL

≈ 0.75 V

≈ 0.2 V

f

OSC

≈ −

1

CT × RT × ln

V

V

≈ 0.75 ×

OSCL
OSCH

1

CT × R

[Hz]

T

Note, however, that the above formulas do not take the rapid charge time, overshoot, and undershoot into

account. See the experimentally determined graph of the oscillator frequency vs. timing capacitance value
provided in the main characteristics section.

3. Error amplifier
This circuit is an npn-transistor input error ampli-

fier that detects and amplifies the DC-DC converter
output voltage, and inputs that signal to a PWM com­parator. The 1.27 V internal reference voltage is
applied to the noninverting input. Arbitrary gain and
phase compensation can be set up by inserting a re­sistor and capacitor in series between the error am­plifier output pin (pin 10) and the inverting input pin
(pin 1). The output voltage V

can be set by resis-

OUT

tor-dividing the output as shown in figure 2.

R1

R2

V

OUT

V

OUT

FB

IN− 1

= 1.27 ×

10

R1 + R2

Error

amplifier

1.27 V

R2

To the PWM

comparator input

Figure 2. Connection method of error amplifier

11

AN8016NSH Voltage Regulators

■ Application Notes (continued)

[4] Function descriptions (continued)

4. Timer latch short-circuit protection circuit
This circuit protects the external main switching element, flywheel diode, choke coil, and other components

against degradation or destruction if an excessive load or a short circuit of the power supply output continues
for longer than a certain fixed period.

The timer latch short-circuit protection circuit detects the output of the error amplifiers. If the DC-DC

converter output voltage drops and an error amplifier output level exceeds 1.27 V, this circuit outputs a low level
and the timer circuit starts. This starts charging the external protection circuit delay time capacitor.

If the error amplifier output does not return to the normal voltage range before that capacitor reaches 1.27

V, the latch circuit latches, the output drive transistors are turned off, and the off-period is set to 100%.

5. Low input voltage malfunction prevention circuit (U.V.L.O.)
This circuit protects the system against degradation or destruction due to incorrect control operation when

the power supply voltage falls during power on or power off.

The low input voltage malfunction prevention circuit detects the internal reference voltage that changes with

the supply voltage level. While the supply voltage is rising, this circuit cuts off the output drive transistor until
the reference voltage reaches 1.6 V. It also sets the off-period to 100%, and at the same time holds the S.C.P. pin
(pin 2) and the SS pin (pin 3) at the low level.

6. PWM comparator
The PWM comparator controls the on-period of the output pulse according to its input voltage. The output

transistors are turned on during periods when the OSC pin (pin 9) triangular waveform is lower than the error
amplifier output pin (pin 10), the SS pin (pin 3), and the IC internally fixed dead-time voltage (about 0.6 V).

The maximum duty is fixed at 80% (typical).
The SS pin provides a constant-current source output of 5 µA (typical), and can be used to implement soft

start operation in which the output pulse on period is gradually increased by connecting an external capacitor to
that pin. Note that the SS pin charge operation completes when the SS pin voltage reaches 1.22 V (typical).

7. Unlatch block
The unlatch circuit holds the S.C.P. fixed at the low level while the SS pin voltage reaches the soft start

operation start-level (about 0.23 V) when power is first applied. This suppresses increases in the short-circuit
protection detection time associated with longer startup times.

8. Output block
The output circuit has a totem pole structure. A constant-current source output with good line regulation can

be set up at an arbitrary voltage by connecting a current setting resistor to the RB pin.

This circuit can provide an output current of up to 50 mA. The output pin has a breakdown voltage of 15 V.

9. On/off control block
The IC can be turned on or off externally. When the Off pin (pin 4) voltage is set by the application of about

1.3 V or higher, the internal reference voltage is turned on, and control operation starts. If the Off pin voltage is
dropped to about 0.8 V or lower, after the S.C.P. pin and SS pin external capacitors discharge, the internal
reference voltage is turned off and IC control operation is stopped. This reduces IC current consumption to 5 µA
or under.

13

Voltage Regulators AN8016NSH

■ Application Notes (continued)

[5] Time constant setup for the timer latch short-circuit protection circuit

Figure 4 shows the structure of the timer latch short-circuit protection circuit. The short-circuit protection

comparator continuously compares a 1.27 V reference voltage with the error amplifier output V

When the DC-DC converter output load conditions are stable, the short-circuit protection comparator holds its
average value, since there are no fluctuations in the error amplifier outputs. At this time, the output transistor Q1
will be in the conducting state, and the S.C.P. pin will be held at about 60 mV.

If the output load conditions change rapidly and a high-level signal (1.27 V or higher) is input to the short­circuit protection comparator's non-inverting input from the error amplifier, the short-circuit protection comparator
will output a low level and the output transistor Q1 will shut off. Then, the external capacitor C
S.C.P. pin will start to charge. When the external capacitor C

is charged to about 1.27 V, the latch circuit will latch

S

and the off-period will be set to 100% with the output held fixed at the low level. Once the latch circuit has latched,
the S.C.P. pin capacitor will be discharged to about 40 mV, but the latch circuit will not reset unless either power
is turned off or the power supply is restarted using on/off control.

The capacitor C

is charged from 60 mV to about 230 mV with a time constant determined by a resistor of 6 kΩ,

S

and is charged from 230 mV to 1.26 V by a constant current of about 1.3 µA.

.

FB

connected to the

S

1) 0.06 ≤ V

V
t

PE1

2) 0.23 ≤ V

SCP

= (0.23 − 0.06) × {1 − exp( −

SCP

[s] ≈ 0.017 × CS [mF]

SCP

1.27 V = 0.23 V + I
t

[s] ≈ 0.80 × CS [µF]

PE2

[s] ≈ t

∴ t

PE

FB 10

IN− 1

[V] ≤ 0.23

[V] ≤ 1.26

CHG

+ t

PE1

PE2

Error amp.

1.27 V

t

PE1

6k · C

t

PE2

×

C

S

≈ 0.817 × CS [µF]

On/off
control

1.27 V

V

CC

S.C.P. comp.

3 kΩ

3 kΩ

Q1

V

)} [V]

S

1 µA

0.23 V

High level detection comparator

1.27 V

SCP

1.27

0.23

0.06

t

PE1

Figure 3. S.C.P. pin charging waveform

U.V.L.O.

Latch

R
S

[V]

Short-circuit detection time t

t

PE2

Internal reference

Output

shutoff

Q

PE

t [s]

C

S.C.P. 2

S

Figure 4. Short-circuit protection circuit

At power supply startup, the output appears to be in the shorted state, the error amplifier output goes to the high
level, and the IC starts to charge the S.C.P. pin capacitor. Therefore, users must select an external capacitor that allows
the DC-DC converter output voltage to rise before the latch circuit in the later stage latches. In particular, care is
required if the soft start function is used, since that function makes the startup time longer.

13

AN8016NSH Voltage Regulators

■ Application Notes (continued)

[6] Setting the soft start time

A soft start function, which gradually increases the width of the output pulses at power on, will be applied if a
capacitor is connected to the SS pin. This can prevent rush currents and overshoot when the power supply is turned
on.

The capacitor C
kΩ, and is charged from 230 mV to 1.22 V by a constant current of about 5 µA.

The following formulas express the soft start time for the duty of up to 50%.

is charged from 60 mV to about 230 mV with a time constant determined by a resistor of 6

SS

1) 0.06 ≤ V

V
t

PE1

2) 0.23 ≤ V

SCP

= (0.23 − 0.06) × {1 − exp( −

SCP

[s] ≈ 0.017 × CS [mF]

SCP

0.52 V = 0.23 V + I
t

[s] ≈ 0.058 × CS [µF]

PE2

[s] ≈ t

∴ t

SS

[V] ≤ 0.23

[V] ≤ 1.26

CHG

+ t

SS1

≈ 0.075 × CS [µF]

SS2

(V)

1.22

0.75

0.52

0.23

0.06
t

SS1

×

FB

OSC

t

SS1

)} [V]

6k · C

S

t

SS2

C

S

SS

t

SS2

Duty: 50%

t (s)

15

Soft start time

DC-DC converter output voltage

Figure 5. Soft start operating waveforms

Voltage Regulators AN8016NSH

■ Application Notes (continued)

[7] Parallel synchronous operation of multiple ICs

Multiple instances of this IC can be operated in parallel. All the ICs will operate at the same frequency if the master

and slave IC OSC pins (pin 9) are connected directly.

1. Notes on S.C.P. operation during parallel operation
In the circuit in figure 6, if either the IC operating in master mode or the IC in slave mode detects a short circuit,

the IC that detected the short circuit will enter latched mode. The latched mode state is a state in which the
output is shut off and both the RB pin and the SS pin are set to the low level. However in this mode, this IC has
an added function that holds the OSC pin at the high level (about 0.8 V).

When OSC pin of the IC that did not enter latched mode goes to the high level, the internally fixed dead- time

voltage (about 0.6 V) will then be lower than the OSC pin voltage, and internal PWM circuit output will stop.
That will cause this IC to go to the output shorted state, and then, this IC will also switch to latched mode.

Therefore, applications that require parallel synchronous operation should adopt the basic circuit structure

shown in figure 6.

2. Usage notes

1) If capacitors are shared as shown in figure 7 to reduce the number of external components:

• The charge current will be doubled.

• The short-circuit protection circuit will not operate if the S.C.P. pin capacitor is shared.

In this circuit, even if the master IC detects a short circuit, the slave IC will not detect that state, so the
S.C.P. pin will remain fixed at the low level state. Note that as a result, the short-circuit protection circuit
will not operate and the IC will continue to operate at the maximum duty drive.

OSC

65

74

83

92

101

AN8016NSH Master

S.C.P.

Figure 6. Slave operation circuit example

2) Note that it is not possible to operate this IC (the AN8016NSH) with the two-channel AN8017SA/AN8018SA
together in parallel synchronous mode.

SS

92

101

AN8016NSH Slave

65

74

83

SSS.C.P.

OSC

65

74

83

92

101

AN8016NSH Master

S.C.P.

NG

Figure 7. Slave operation circuit example

92

101

AN8016NSH Slave

65

74

83

SS

15

AN8016NSH Voltage Regulators

■ Application Circuit Examples

[1] Application circuit (Step-up circuit)

330 pF

12 kΩ

390 Ω

0.1 µF

1 kΩ

FB10IN− 1

OSC9S.C.P. 2

RB8SS 3

AN8016NSH

333 pF

103 pF

6.8 kΩ
20 kΩ

GND7Off 4

1.5 V

V
3 V

Out6V

5

CC

IN

1 µF

47 µH

MA2Q738 (MA738∗)

2SD2408

Note) ∗: Former part number

Q1

SBD

10 µF

V

OUT

5 V
200 mA

The figure shows a step-up circuit that converts a 3 V input to a 5 V output.

The AN8016NSH output stage has a totem pole circuit configuration, and can directly drive an n-channel
MOSFET while minimizes switching loss and increasing efficiency. In this case, replace the npn transistor with an
n-channel MOSFET in above circuit.

[2] Notes on direct n-channel MOSFET drive

1. Select an n-channel MOSFET with a low input

capacitance.

The AN8016NSH was designed to drive bipolar
transistors, and adopts a circuit structure that can pro­vide a constant-current (50 mA maximum) output
source current. Furthermore, it has a sink current ca­pacity of about 50 mA. This means that designs must
be concerned about increased power dissipation due
to increased rise and fall times. If problems occur, an
inverter may be inserted as shown in figure 1 to pro­vide amplification.

2. Use an n-channel MOSFET of a low gate threshold
voltage.

Since the AN8016NSH Out pin high-level output

voltage is V

− 1.0 V (minimum), a low VT MOSFET

CC

with an adequately low on-resistance must be used.
Also, if a large V

is required, one solution is to use

GS

a transformer as shown in figure 2, and apply a volt­age of twice the input voltage to the IC's V

CC

pin.

V

IN

6

Out

Figure 1. Output boosting circuit

V

IN

V

CC

SBD

5

6

Out

VCC ≈ 2 × VIN − V

Figure 2. Gate drive voltage boosting technique

SBD

SBD

V

OUT

V

OUT

D

17

Voltage Regulators AN8016NSH

■ Application Circuit Examples (continued)

[2] Notes on direct n-channel MOSFET drive (continued)

3. Notes on printed circuit board pattern layout

Observe the following recommendations on printed circuit board pattern layout to achieve low noise and high

efficiency.

1) Use extremely wide lines for the ground lines, and isolate the IC ground from the power system ground.

2) Make the lines in the high-current system as wide as possible.

3) Position the input filter capacitor C3 as close as possible to the V
are no other paths for switching noise to enter the IC.

4) Keep the length of the line between the Out pin and the switching device (either a MOSFET or other
transistor) as short as possible to provide a clean switching waveform to the switching device.

5) Use a relatively long line for the low-impedance side of the output voltage detection resistor R2.

V

IN

RB8

FB10IN− 1

OSC9

GND7

Out6V

and ground pins, and assure that there

CC

(2)

SBD

Q1

(4)

V

OUT

GND

(1)

[3] Evaluation board

AN8016NSH

S.C.P. 2

24
kΩ
R2

SS 3

Off V

5

CC

Off 4

C3

IN

L1

C3

C1C2

R1

AN8016NSH

R2

DC-DC CONVERTER BOARD

R4

R3

(3)

+

SBD

Q1

BCE

C4

R5

(5)

V

OUT

+

C6

GND

R6

C5

17