MIC2829 Datasheet, PDF (32/52 Pages) Micrel Semiconductor – 3G/4G HEDGE/LTE PMIC with Six Buck Converters, Eleven LDOs and SIM Card Level Translation

Micrel Inc.
FB5 and FB6
The feedback pin (FB5, FB6) allows DC5 and DC6
output voltage to be set by applying an external resistor
network. The internal reference voltage is 1V and the
recommended value of R_BOTTOM is 20kΩ or below. A
feed-forward capacitor (C_FF) of 120pF should be placed
parallel to R_TOP to improve stability and transient
response. This does not impact the output voltage
setting. The output voltage is calculated from the
equation below.
VOUT = 1V ⎜⎛ ^RTOP + 1⎟⎞
⎝ ^20kΩ ⎠
VOUT
CFF
RTOP
RBOTTOM
Figure 2. Feedback Resistor Network
SW
The switch pin (SW1 to SW6) connects directly to one
end of the inductor and provides the current path during
switching cycles. The other end of the inductor is
connected to the output of the buck regulator. Due to the
high speed switching on this pin, the switch node should
be routed away from sensitive nodes whenever possible.
VSC2
The voltage scaling pin (VSC2) is used to switch the
output of DC2 between two different voltage levels. A
high on the VSC2 pin will set the output voltage of DC2
to the higher voltage. A low on the VSC2 pin will set the
output voltage to the lower voltage. Do not leave floating.
LSPWR
The level shifter input supply pin (LSPWR) provides
power to the level shifter. A minimum 1µF input capacitor
with a minimum voltage rating of 6.3V placed close to
LSPWR and ground (AGND1, AGND2) is required.
Refer to the layout recommendations for details.
SIMPWR
SIM power (SIMPWR) provides power to the SIM Card.
A minimum 1µF input capacitor with a minimum voltage
rating of 6.3V to ground (AGND1, AGND2) is required.
Refer to the layout recommendations for details.
MIC2829
VSLS
VSLS selects the level shifted voltage for the SIM Card.
A high logic voltage on VSLS selects the level shifter to
3V. A low logic voltage on VSLS selects the level shifter
to 1.8V. Do not leave floating.
RSTIN, SIMRST
RSTIN is the digital reset input for the SIM Card and
translates to SIMRST through the digital level shifter. It is
one directional. If VSLS is low, then the input at RSTIN
will be level shifted to 1.8V at the SIMRST output. If
VSLS is high, then the input at RSTIN will be level
shifted to 3V at the SIMRST output.
CLKIN, SIMCLK
CLKIN is the digital input clock for SIM card. The CLKIN
translates to SIMCLK and is one directional. If VSLS is
low, then the input at CLKIN will be level shifted to 1.8V
at the SIMCLK output. If VSLS is high, then the input at
CLKIN will be level shifted to 3V at the SIMCLK output.
DATA, SIMIO
DATA is the digital data for the SIM Card. The DATA
translate to SIMIO through the digital level shifter and is
bi-directional using internal pull ups. If VSLS is low, then
the level shifted output is 1.8V at the SIMIO output. If
VSLS is high, then the level shifted output is 3V at the
SIMIO output. Since DATA and SIMIO are bi-directional,
the input at SIMIO is level shifted to equal the LSPWR
voltage at the DATA output.
G1 – G9
The G1 through G9 pins are not internally connected.
They serve as thermal relief and should be connected to
ground (AGND1, AGND2) to maximize the heat
dissipation. See layout recommendations for details.
May 2010
32
M9999-051410-B