MIC26950 Datasheet PDF - MICREL

www.Datasheet-PDF.com

MIC26950
MICREL

Part Number MIC26950
Description 12A Hyper Speed Control Synchronous DC-DC Buck Regulator
Page 28 Pages


MIC26950 datasheet pdf
Download PDF
MIC26950 pdf
View PDF for Mobile

No Preview Available !

MIC26950
12A Hyper Speed ControlTM
Synchronous DC-DC Buck Regulator
SuperSwitcher IITM
General Description
The Micrel MIC26950 is a constant-frequency, synchronous
buck regulator featuring a unique digitally modified adaptive
ON-time control architecture. The MIC26950 operates over
an input supply range of 4.5V to 26V and provides a
regulated output at up to 12A of output current. The output
voltage is adjustable down to 0.8V with a typical accuracy of
±1%, and the device operates at a switching frequency of
300kHz.
Micrel’s Hyper Speed ControlTM architecture allows for ultra-
fast transient response while reducing the output capacitance
and also makes (High VIN)/(Low VOUT) operation possible.
This digitally modified adaptive tON ripple control architecture
combines the advantages of fixed-frequency operation and
fast transient response in a single device.
The MIC26950 offers a full suite of protection features to
ensure protection of the IC during fault conditions. These
include undervoltage lockout to ensure proper operation
under power-sag conditions, internal soft-start to reduce
inrush current, fold-back current limit, “hiccup” mode short-
circuit protection and thermal shutdown.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Features
Hyper Speed ControlTM architecture enables
- High delta V operation (VIN = 26V and VOUT = 0.8V)
- Small output capacitance
4.5V to 26V input voltage
Adjustable output from 0.8V to 5.5V (±1% accuracy)
Any CapacitorTM Stable
- Zero-ESR to high-ESR output capacitance
12A output current capability
300kHz switching frequency
Internal compensation
Up to 95% efficiency
6ms internal soft-start
Foldback current-limit and “hiccup” mode short-circuit
protection
Thermal shutdown
Supports safe start-up into a pre-biased load
–40°C to +125°C junction temperature range
28-pin 5mm X 6mm MLF® package
Applications
Distributed power systems
Communications/networking infrastructure
Set-top box, gateways and routers
Printers, scanners, graphic cards and video cards
____________________________________________________________________________________________________________
Typical Application
100
95
90
85
80
75
70
65
60
0
Efficiency (VIN = 12V)
vs. Output Current
5.0V
3.3V
2.5V
1.5V
1.0V
3 6 9 12
OUTPUT CURRENT (A)
15
Hyper Speed Control, SuperSwitcher II and Any Capacitor are trademarks of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
July 2011
M9999-070111-C



No Preview Available !

Micrel, Inc.
Ordering Information
Part Number
MIC26950YJL
Voltage
Adjustable
Switching Frequency
Junction Temperature
Range
300kHz
–40°C to +125°C
Package
28-pin 5mm × 6mm MLF®
Pin Configuration
MIC26950
Lead Finish
Pb-Free
28-Pin 5mm X 6mm MLF® (YJL)
Pin Description
Pin
Number
13,14,15,
16,17,18,
19
Pin Name
PVIN
24 EN
25 FB
26 SGND
27 VDD
2, 5, 6,
7, 8, 21
PGND
22 CS
Pin Function
High-Side N-internal MOSFET Drain Connection (Input): The PVIN operating voltage range is from
4.5V to 26V. Input capacitors between PVIN and the power ground (PGND) are required.
Enable (Input): A logic level control of the output. The EN pin is CMOS-compatible. Logic high or
floating = enable, logic low = shutdown. In the off state, supply current of the device is greatly reduced
(typically 0.8mA).
Feedback (Input): Input to the transconductance amplifier of the control loop. The FB pin is regulated
to 0.8V. A resistor divider connecting the feedback to the output is used to adjust the desired output
voltage.
Signal ground. SGND must be connected directly to the ground planes. Do not route the SGND pin to
the PGND Pad on the top layer.
VDD Bias (Input): Power to the internal reference and control sections of the MIC26950. The VDD
operating voltage range is from 4.5V to 5.5V. A 2.2µF ceramic capacitor from the VDD pin-to-PGND is
recommended for clean operation.
Power Ground. PGND is the ground path for the MIC26950 buck converter power stage. The PGND
pin connects to the sources of low-side N-Channel internal MOSFETs, the negative terminals of input
capacitors, and the negative terminals of output capacitors. The loop for the power ground should be
as small as possible and separate from the Signal ground (SGND) loop.
Current Sense (Input): High current output driver return. The CS pin connects directly to the switch
node. Due to the high speed switching on this pin, the CS pin should be routed away from sensitive
nodes. CS pin also senses the current by monitoring the voltage across the low-side internal
MOSFET during OFF-time.
July 2011
2 M9999-070111-C



No Preview Available !

Micrel, Inc.
MIC26950
Pin Description (Continued)
Pin
Number
20
4, 9, 10,
11, 12
23
1, 3, 28
Pin Name
BST
SW
VIN
NC
Pin Function
Boost (Output): Bootstrapped voltage to the high-side N-channel internal MOSFET driver. A Schottky
diode is connected between the VDD pin and the BST pin. A boost capacitor of 0.1μF is connected
between the BST pin and the SW pin.
Switch Node (Output): Internal connection for the high-side MOSFET source and low-side MOSFET
drain.
Power Supply Voltage (Input): Requires bypass capacitor to SGND.
No Connect.
July 2011
3 M9999-070111-C



No Preview Available !

Micrel, Inc.
MIC26950
Absolute Maximum Ratings(1,2)
PVIN to PGND................................................ 0.3V to +28V
VIN to PGND ....................................................0.3V to PVIN
VDD to PGND ................................................... 0.3V to +6V
VSW, VCS to PGND .............................. 0.3V to (PVIN +0.3V)
VBST to VSW ........................................................ 0.3V to 6V
VBST to PGND .................................................. 0.3V to 34V
VEN to PGND ...................................... 0.3V to (VDD + 0.3V)
VFB to PGND....................................... 0.3V to (VDD + 0.3V)
PGND to SGND ........................................... 0.3V to +0.3V
Junction Temperature .............................................. +150°C
Storage Temperature (TS).........................65°C to +150°C
Lead Temperature (soldering, 10sec)........................ 260°C
Operating Ratings(3)
Supply Voltage (PVIN, VIN)............................... 4.5V to 26V
Output Voltage Range (VOUT)........................... 0.8V to 5.5V
Bias Voltage (VDD)............................................ 4.5V to 5.5V
Enable Input (VEN) ................................................. 0V to VDD
Junction Temperature (TJ) ........................ 40°C to +125°C
Maximum Power Dissipation......................................Note 4
Package Thermal Resistance(4)
5mm x 6mm MLF®(θJA) .....................................36°C/W
Electrical Characteristics(5)
PVIN = VIN = 12V, VDD = 5V; VBST – VSW = 5V; TA = 25°C, unless noted. Bold values indicate 40°C TJ +125°C.
Parameter
Condition
Min.
Typ.
Power Supply Input
Input Voltage Range (VIN, PVIN)
4.5
VDD Bias Voltage
Operating Bias Voltage (VDD)
Undervoltage Lockout Trip Level
UVLO Hysteresis
VDD Rising
4.5
2.4
Quiescent Supply Current
Shutdown Supply Current
VFB = 1.5V
VDD = VBST = 5.5V, VIN = 26V
SW = unconnected, VEN = 0V
Reference
Feedback Reference Voltage
Load Regulation
Line Regulation
FB Bias Current
0°C TJ 85°C (±1.0%)
40°C TJ 125°C (±1.5%)
IOUT = 0A to 12A
VIN = (VOUT + 3.0V) to 26V
VFB = 0.8V
0.792
0.788
Enable Control
EN Logic Level High
EN Logic Level Low
EN Bias Current
4.5V < VDD < 5.5V
4.5V < VDD < 5.5V
VEN = 0V
1.2
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kin series with 100pF.
3. The device is not guaranteed to function outside operating range.
4. PD(MAX) = (TJ(MAX) – TA)/ θJA, where θJA depends upon the printed circuit layout. See “Applications Information.”
5. Specification for packaged product only.
5
2.7
50
1.4
0.7
0.8
0.8
0.2
0.1
5
0.85
0.78
50
Max.
26
5.5
3.2
3
2
0.808
0.812
0.4
Units
V
V
V
mV
mA
mA
V
%
%
nA
V
V
µA
July 2011
4 M9999-070111-C



MIC26950 datasheet pdf
Download PDF
MIC26950 pdf
View PDF for Mobile


Related : Start with MIC2695 Part Numbers by
MIC26950 12A Hyper Speed Control Synchronous DC-DC Buck Regulator MIC26950
MICREL
MIC26950 pdf

Index :   0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   

This is a individually operated, non profit site. If this site is good enough to show, please introduce this site to others.
Since 2010   ::   HOME   ::   Contact