Micrel MIC2186 User Manual

MIC2186 Micrel

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MIC2186

Low Voltage PWM Control IC

Final Information

General Description

Micrel’s MIC2186 is a high efficiency boost PWM control IC.
With its wide input voltage range of 2.9V to 14V, the MIC2186
can be used to efficiently boost voltages in 1- or 2-cell Li Ion
battery powered applications, as well as to boost voltages in
fixed 3.3V, 5V, or 12V systems. Its powerful 1.6Ω output
driver allows the MIC2186 to supply large output currents with
the selection of proper external MOSFETs.

The MIC2186 can be configured to operate at 100kHz,
200kHz, or 400kHz. With it’s fixed frequency PWM architec­ture, and easily synchronized drive, the MIC2186 is ideal for
noise-sensitive telecommunications applications.

MIC2186 also features a low current shutdown mode of

0.5µA and programmable undervoltage lockout. A manually
selectable SKIP Mode allows high efficiencies in light load
situations.

The MIC2186 is available in 16 pin SOIC and QSOP package
options with an operating range from –40°C to 125°C.

Features

• Input voltage range: 2.9V to 14V

• 1.6Ω output driver

• Oscillator frequency of 100kHz/200kHz/400kHz

• Frequency sync to 600kHz

• Front edge blanking

• PWM Current Mode Control

• Selectable light load SKIP mode

• 600µA quiescent current (SKIP-Mode)

• 0.5µA shutdown current

• Cycle-by-Cycle current limiting

• Frequency foldback protection

• Adjustable under-voltage lockout

• Precision 1.245V reference output

• 16 pin SOIC and QSOP package options

• Selectable 50% maximum duty cycle for flyback applica-

tions

Applications

• DC power distribution systems

• Wireless Modems

• ADSL line cards

• SLIC power supplies

• 1-and 2-cell Li Ion battery operated equipment

T ypical Application

= 3.3V

V

IN

C

IN

120µF

20V

Ordering Information

Part Number Frequency Voltage Ambient Temp. Range Package

MIC2186BM 100kHz/200kHz/400kHz Adj –40°C to +125°C 16-lead SOP
MIC2186BQS 100kHz/200kHz/400kHz Adj –40°C to +125°C 16-lead QSOP

VINP

FB

CSH

MBR2535CT

16

6

14

9

12

Si4404DY
(x2)

4.5mΩ

V

OUT

C

OUT

150µF(x2)
20V

= 12V

12V Output Efficienc

95
90
85
80
75
70

EFFICIENCY (%)

65
60

0 0.5 1 1.5 2 2.5 3

OUTPUT CURRENT (A)

VIN = 3.3V

1

VINA

7

EN/UVLO

13

HIDC

15

FREQ/2

10

VDD

4

COMP

8

VREF

2

SKIP

11

SYNC

2.2µH

MIC2186

SS

3

SGND

OUTN

PGND

5

Adjustable Output Boost Converter

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

July 2002 1 MIC2186

MIC2186 Micrel

Pin Configuration

COMP

SGND

EN/UVLO

VREF

16-pin Narrow Body SOP (M)

Pin Description

Pin Number Pin Name Pin Function

1 VINA Input voltage to control circuitry (2.9V to 14V).
2 SKIP SKIP (Input): Regulator operates in PWM mode (no pulse skipping) when

3 SS Soft start reduces the inrush current and delays and slows the output voltage

4 COMP Compensation (Output): Internal error amplifier output. Connect to a

5 SGND Small signal ground: must be routed separately from other grounds to the (-)

6 FB Feedback Input - regulates FB to 1.245V.
7 EN/UVLO Enable/Undervoltage Lockout (input): A low level on this pin will power down

8 VREF The 1.245V reference is available on this pin. A 0.1µF capacitor should be

9 CSH The (+) input to the current limit comparator. A built in offset of 100mV

10 VDD 3V internal linear-regulator output. Vdd is also the supply voltage bus for the

11 SYNC Frequency Synchronization (Input): Connect an external clock signal to

12 PGND MOSFET driver power ground, connects to the bottom of the current sense

13 HIDC High Duty Cycle. Sets duty cycle and frequency along with Freq/2. Logic

14 OUTN High current drive for N channel MOSFET. Voltage swing is from ground to

15 FREQ/2 Sets duty cycle and frequency along with HiDC. See applications section for

16 VINP Power input voltage to the gate drive circuitry (2.9V to 14V). This pin is

SKIP

SS

FB

1VINA
2
3
4
5
6
7
8

16 VINP

FREQ/2

15

OUTN

14

HIDC

13

PGND

12

SYNC

11

VDD

10

CSH

9

16-pin QSOP (QS)

pin is pulled low, and skip mode when raised to Vdd. There is no automatic
switching between PWM and skip mode available on this device.

rise time. A 5µA current source will charge the capacitor up to Vdd.

capacitor or series RC network to compensate the regulator’s control loop.

terminal of Cout.

the device, reducing the quiescent current to under 0.5µA. This pin has two
separate thresholds, below 1.5V the output switching is disabled, and below

0.9V the device is forced into a complete micropower shutdown. The 1.5V
threshold functions as an accurate undervoltage lockout (UVLO) with 135mV
hysteresis.

connected form this pin to SGnd.

between CSH and SGnd in conjunction with the current sense resistor sets
the current limit threshold level. This is also the (+) input to the current
amplifier.

chip. Bypass to SGND with 1µF. Maximum source current is 0.5mA.

synchronize the oscillator. Leading edge of signal above 1.5V starts switch­ing cycle. Connect to SGND if not used.

resistor and the (–) terminal of CIN.

HIGH sets 85% maximum duty cycle. Logic LOW sets 50% maximum duty
cycle. See applications section for more information.

VIN. RON is typically 1.6Ω.

more information.

normally connected to the output voltage.

MIC2186 2 July 2002

MIC2186 Micrel

Absolute Maximum Ratings (Note 1)

Supply Voltage (VINA, VINP) .........................................15V

Digital Supply Voltage (V
SKIP Pin Voltage (V

SKIP

Max Duty Cycle Pin Voltage (V
Frequency Divider Pin Voltage (V
Sync Pin Voltage (V

SYNC

Comp Pin Voltage (V
Feedback Pin Voltage (V
Enable Pin Voltage (V
Current Sense Voltage (V
Power Dissipation (P

) ...........................................7V

DD

) ................................. –0.3V to 7V

)................ –0.3V to 7V

HIDC

) ........ –0.3V to 7V

FREQ/2

) ................................ –0.3V to 7V

).............................. –0.3V to 3V

COMP

) ............................ –0.3V to 3V

FB

EN/UVLO

)

D

) ...................... –0.3V to 15V

)......................... –0.3V to 1V

CSH

Operating Ratings (Note 2)

Supply Voltage (VINA, VINP) ........................ +2.9V to +14V

Operating Ambient Temperature.........–40°C ≤ T

Junction Temperature ....................... –40°C ≤ T

PackageThermal Resistance

16-lead SOP ...............................................100°C/W

θ

JA

θJA 16-lead QSOP.............................................163°C/W

≤ +85°C

A

≤ +125°C

J

16 lead SOP ..............................400mW @ TA = 85°C

16 lead QSOP ...........................245mW @ TA = 85°C

Ambient Storage Temp ............................–65°C to +150°C

ESD Rating (Note 3)

Electrical Characteristics

VINA = 5V, VINP = V
indicate –40°C < TJ < +125°C.

Parameter Condition Min Typ Max Units
Regulation

Feedback Voltage Reference (±1%) 1.233 1.245 1.258 V

Feedback Bias Current 50 nA
Output Voltage Line Regulation 3V ≤ VINA ≤ 9V +0.08 % / V
Output Voltage Load Regulation 0mV ≤ CSH ≤ 75mV –1.2 %

Input & VDD Supply

VINA Input Current, PWM mode V
VINP Input Current, PWM mode V
VINA Input Current, SKIP mode V
Shutdown Quiescent Current VEN/UVLO = 0V; (I
Digital Supply Voltage (VDD) IL = 0 2.82 3.0 3.18 V
Digital Supply Load Regulation IL = 0 to 0.5mA 0.03 V
Undervoltage Lockout VDD upper threshold (turn on threshold) 2.9 2.75 V

Reference Output (V

Reference Voltage (±1.5%) 1.226 1.245 1.264 V

Reference Voltage Line 5V < VinA < 9V 2 mV
Regulation

Reference Voltage Load 0 < I
Regulation

= 12V, SKIP = 0V, FREQ/2 = 0V, HiDC = 3V, V

OUT

(±2%) 1.220 1.270 V
3V ≤ VINA ≤ 9V; 0mV ≤ CSH ≤ 75mV; (±3%) 1.208 1.245 1.282 V

= 0V 0.7 mA

SKIP

= 0V (excluding external MOSFET gate current) 2.8 mA

SKIP

= 5V 0.6 mA

SKIP

+ I

VINA

VDD lower threshold (turn off threshold) 2.65 V

)

REF

(±2.5%) 1.213 1.276 V

< 100µA1mV

REF

= 0V, TJ = 25°C, unless otherwise specified. Bold values

CSH

) 0.5 5 µA

VINP

July 2002 3 MIC2186

MIC2186 Micrel

Parameter Condition Min Typ Max Units
Enable/UVLO

Enable Input Threshold 0.6 0.9 1.2 V
UVLO Threshold 1.4 1.5 1.6 V
UVLO Hysteresis 140 mV
Enable Input Current V

EN/UVLO

Soft Start

Soft Start Current 5 µA

Current Limit

Current Limit Threshold Voltage (Voltage on CSH to trip current limit) 80 100 120 mV

Error Amplifier

Error Amplifier Gain 20 V/V

Current Amplifier

Current Amplifier Gain 3.7 V/V

SKIP Input

SKIP Threshold 0.6 1.4 2.2 V
SKIP Input Current V

SKIP

HIDC Input

HIDC Threshold 0.6 1.4 2.2 V

Oscillator Section

Oscillator Frequency (fO) 360 400 440 kHz
Maximum Duty Cycle V

FB

VFB = 1.0V, V
Minimum On Time VFB = 1.5V, V
FREQ/2 Frequency (fO)V

HiDC

Frequency Foldback Threshold Measured on FB 0.3 V
Frequency Foldback Frequency V

HiDC

SYNC Threshold Level 0.6 1.4 2.2 V
SYNC Input Current 0.1 5 µA
SYNC Minimum Pulse Width 200 ns
SYNC Capture Range Note 4

Gate Drivers

Rise/Fall Time CL = 3300pF 50 ns
Output Driver Impedance source; VINP = 12V 1.8 4 Ω

sink; VINP = 12V 1.6 3.5 Ω

source; VINP =5V 2.6 Ω

sink; VINP = 5V 2.4 Ω

= 5V 0.2 5 µA

= 3V 0.1 5 µA

= 1.0V, V

= 3V, V

= 3V, V

= 3V 85 %

HIDC

= 0V 50

HIDC

= 3V 180 ns

HiDC

= 3V 170 200 230 kHz

FREQ/2

= 0V 90 kHz

FREQ/2

fO + 15 %

600 kHz

Note 1. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when

Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD sensitive. Handling precautions recommended.
Note 4. See application information for limitations on maximum operating frequency.

operating the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction
temperature, T

, the junction-to-ambient thermal resistance, θJA, and the ambient temperature, TA.

J(max)

MIC2186 4 July 2002

MIC2186 Micrel

0

0.5

1

1.5

2

2.5

3

3.5

4

0 2 4 6 8 10 12 14 16

I

Q

(mA)

INPUT VOLTAGE (V

INA

)

Quiescent Current vs.

Input Voltage(PWM Mode)

400kHz

200kHz

100kHz

VINP =12V

DC

IQ = I

QVINA+IQVINP

)

)

1.244

1.2442

1.2444

1.2446

1.2448

1.245

1.2452

0 2 4 6 8 10 12 14 16

REFERENCE VOLTAGE (V)

INPUT VOLTAGE (V

INA

)

Reference Voltage

vs. Input Voltage

VINP = 12V

DC

2.80

2.85

2.90

2.95

3.00

3.05

3.10

02468101214

VDD (V)

INPUT VOLTAGE (V

INA

)

VDD vs.

Input Voltage

VINP = 12V

DC

0

50

100

150

200

250

300

02468101214

IENABLE (µA)

VENABLE (V)

Ienable vs.

Venable

VINP = 12V

DC

VINA = 5V

DC

85°C

–40°C

20°C

Typical Characteristics

Quiescent Current vs.

Temperature (SKIP Mode)

0.8

0.7

0.6

0.5

(mA)

0.4

0.3

Q(SKIP)

I

0.2

0.1
0

-40 -20 0 20 40 60 80 100

VINA = 5V

DC

VINP = 12V
IQ = I

QVINA+IQVINP

TEMPERATURE (°C)

DC

Quiescent Current vs.

Input Voltage(PWM Mode

4

3.5
3

2.5

(mA)

2

1.5

Q(PWM)

I

1

0.5
0

0 2 4 6 8 10 12 14 16

INPUT VOLTAGE (V

VINP = 12V

VINP = 9V

VINP = 5V

IQ = I

QVINA

fS = 400kHz

+ I

INA

QVINP

)

Quiescent Current vs.

Temperature (PWM Mode)

3.65

3.6

3.55

(mA)

3.5

Q(PWM)

3.45

I

3.4

3.35

-60 -40 -20 0 20 40 60 80 100

VINA = 5V

DC

VINP = 12V
IQ = I

DC

QVINA+IQVINP

TEMPERATURE (°C)

Quiescent Current vs.

Input Voltage (SKIP Mode

0.9

0.85

0.8

0.75
VINP = 5V

0.7

(mA)

Q

I

0.65

0.6

0.55

0.5
0 2 4 6 8 10 12 14 16

INPUT VOLTAGE (V

VINP = 9V

DC

VINP = 12V

INA

DC

DC

)

1.2451

1.245

1.2449

1.2448

1.2447

1.2446

1.2445

1.2444

REFERENCE VOLTAGE (V)

1.2443

3.035

3.030

3.025

3.020

July 2002 5 MIC2186

3.015

VDD (V)

3.010

3.005

3.000

2.995

Reference Voltage

vs. Reference Current

VINP = 12V

VINA = 5V

0 20406080100120

REFERENCE CURRENT (µA)

DC

DC

VDD vs.

Load Current

VINP = 12V

VINA = 5V

0 0.2 0.4 0.6 0.8 1 1.2

IVDD (mA)

DC

DC

Reference Voltage

vs. Temperature

1.2454

1.2452

1.2450

1.2448

1.2446

1.2444

1.2442

1.2440

1.2438

REFERENCE VOLTAGE (V)

1.2436

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

VINP = 12V

VINA = 5V

VDD vs.

Temperature

3.08
VINP = 12V

3.06

VINA = 5V

3.04

3.02

3.00

VDD (V)

2.98

2.96

2.94

-60 -40 -20 0 20 40 60 80 100

DC

DC

TEMPERATURE (°C)

DC

DC