MIC2185 Datasheet, PDF (1/15 Pages) Micrel Semiconductor – Low Voltage Synchronous Boost PWM Control IC

MIC2185
Micrel
MIC2185
Low Voltage Synchronous Boost PWM Control IC
Final Information
General Description
Features
Micrel’s MIC2185 is a high efficiency synchronous boost • Input voltage range: 2.9V to 14V
PWM control IC. With its wide input voltage range of 2.9V to • 95% efficiency
14V, the MIC2185 can be used to efficiently boost voltages in • Oscillator frequency of 200kHz/400kHz
1- or 2-cell Li Ion battery powered applications, as well as • Frequency sync to 600kHz
fixed 3.3V and 5V systems. Its powerful 5Ω output drivers • 0.5µA shutdown current
allow the MIC2185 to supply large output currents with the • Two 5Ω output drivers
selection of the proper external MOSFETs.
• Front edge blanking
With it’s fixed frequency PWM architecture, and easily syn-
chronized drive, the MIC2185 is ideal for noise-sensitive
telecommunications applications. The nominal 400kHz oper-
ating frequency of the MIC2185 can be divided by two,
allowing the device to be externally synchronized to frequen-
cies below 400kHz.
The MIC2185 also features a low current shutdown mode and
a programmable undervoltage lockout. A skipped pulse mode
• PWM Current Mode Control
• Cycle-by-Cycle current limiting
• Frequency foldback protection
• Adjustable under-voltage lockout
• Precision 1.245V reference output
• 16 pin SOIC narrow body package and 16 pin QSOP
package
Applications
of operation can be manually set to achieve higher efficien- _{• 3.3V to 5V conversion in telecom systems}
cies at light load conditions.
• Satellite Phones
The MIC2185 is available in a 16 pin SOIC package and 16 • Cable Modems
pin QSOP package with an ambient temperature operating • 1-and 2-cell Li Ion battery operated equipment
range from –40°C to 85°C.
Ordering Information
Part Number
MIC2185BM
MIC2185BQS
Frequency Voltage
200/400kHz Adj
200/400kHz Adj
Junction Temp. Range
–40°C to +125°C
–40°C to +125°C
Package
16-lead SOP
16-lead QSOP
Typical Application
V_IN = 3.3V
2.4µH
C_IN
1
VINA
14
OUTP
7 _EN/UVLO
VINP ¹⁶
15 _FREQ/2
FB ⁶
10 _VDD
4 _COMP
MIC2185
OUTN ¹³
8 _VREF
11
SYNC
CSH ⁹
2 _SKIP
SS
3
PGND ¹²
SGND
5
Si9803DY (x2)
Si4884DY (x2)
8mΩ
V_OUT = 5V
C_OUT
5V Output Efficiency
100
95
90
85
80
75
V_IN = 3.3V
200kHz PWM
700
1
2
3
4
5
OUTPUT CURRENT (A)
Adjustable Output Synchronous Boost Converter
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
May 2002
1
MIC2185