MIC2198 Datasheet, PDF (2/15 Pages) Micrel Semiconductor – 500kHz 4mm × 4mm Synchronous Buck Controller

MIC2198
Ordering Information
Part Number
MIC2198BML
Voltage
Adj
Temperature Range
–40°C to +125°C
Package
12-lead 4×4 MLF™
Pin Configuration
COMP 1
EN/UVLO 2
FB 3
CSH 4
VOUT 5
VIN 6
12 HSD
11 VSW
10 BST
9 GND
8 LSD
7 VDD
4×4 MLF-12L (ML)
Micrel
Pin Description
Pin Number
1
2
Pin Name
COMP
EN/UVLO
3
FB
4
CSH
5
VOUT
6
VIN
7
VDD
8
LSD
9
GND
10
BST
11
VSW
12
HSD
Pin Function
Compensation (Output): Internal error amplifier output. Connect to capacitor
or series RC network to compensate the regulator control loop.
Enable/Undervoltage Lockout (Input): Low-level signal powers down the
controller. Input below the 2.5V threshold disables switching and functions
as an accurate undervoltage lockout (UVLO). Input below the threshold
forces complete micropower (<0.1µA) shutdown.
Feedback (Input): Regulates FB pin to 0.8V. See “Applications Information”
for resistor divider calculations.
Current-Sense High (Input): Current limit comparator non-inverting input. A
built-in offset of 75mV between CSH and V_OUT pins in conjunction with the
current-sense resistor set the current limit threshold level. This is also the
non-inverting input to the current sense amplifier.
Current-Sense Low (Input): Output voltage feedback input and inverting
input for the current limit comparator and the current sense amplifier.
Unregulated Input (Input): +4.5V to +32V supply input.
5V Internal Linear-Regulator (Output): V_DD is the external MOSFET gate
drive supply voltage and internal supply bus for the IC. Bypass to GND with
4.7µF.
Low-Side Drive (Output): High-current driver output for low-side N-Channel
MOSFET. Voltage swing is between ground and V_DD.
Ground (Return).
Boost (Input): Provides drive voltage for the high-side MOSFET driver. The
drive voltage is higher than the input voltage by V_DD minus a diode drop.
Switch (Return): High-side MOSFET driver return.
High-Side Drive (Output): High-current driver output for high-side MOSFET.
This node voltage swing is between ground and V_IN +5V minus a diode drop.
MIC2198
2
November 2004