Datasheet

C
SS
= 3.3 nF
C
O
= 100 PF
PVIN
AVIN
EN
SS
SGND
PGND
SNS
SW
LM2852Y
+
V
OUT
= 1.5V
I
LOAD
= 0A to 2A
L
O
= 10 PH
C
IN
= 47 PF
1 PF
PVIN = 3.3V
AVIN = 5V
LM2852
SNVS325D –JANUARY 2005–REVISED APRIL 2013 www.ti.com
OUTPUT FILTER CAPACITORS
The capacitors that may be used in the output filter with the LM2852 are limited in value and ESR range
according to Table 1. Below are some examples of capacitors that can typically be used in an LM2852
application.
Table 3. LM2852 Output Filter Capacitors
Capacitance (µF) Part Number Chemistry Vendor
10 GRM31MR61A106KE19 Ceramic Murata
10 GRM32DR61E106K Ceramic Murata
68 595D686X_010C2T Tantalum Vishay - Sprague
68 595D686X_016D2T Tantalum Vishay - Sprague
100 595D107X_6R3C2T Tantalum Vishay - Sprague
100 595D107X_016D2T Tantalum Vishay - Sprague
100 NOSC107M004R0150 Niobium Oxide AVX
100 NOSD107M006R0100 Niobium Oxide AVX
120 595D127X_004C2T Tantalum Vishay - Sprague
120 595D127X_010D2T Tantalum Vishay - Sprague
150 595D157X_004C2T Tantalum Vishay - Sprague
150 595D157X_016D2T Tantalum Vishay - Sprague
150 NOSC157M004R0150 Niobium Oxide AVX
150 NOSD157M006R0100 Niobium Oxide AVX
220 595D227X_004D2T Tantalum Vishay - Sprague
220 NOSD227M004R0100 Niobium Oxide AVX
220 NOSE227M006R0100 Niobium Oxide AVX
SPLIT-RAIL OPERATION
The LM2852 can be powered using two separate voltages for AVIN and PVIN. AVIN is the supply for the control
logic; PVIN is the supply for the power FETs. The output filter components need to be chosen based on the
value of PVIN. For PVIN levels lower than 3.3V, use output filter component values recommended for 3.3V. PVIN
must always be equal to or less than AVIN.
SWITCH NODE PROTECTION
The LM2852 includes protection circuitry that monitors the voltage on the switch pin. Under certain conditions,
switching is disabled in order to protect the switching devices. One result of the protection circuitry may be
observed when power to the LM2852 is applied with no or light load on the output. The output regulates to the
rated voltage, but no switching may be observed. As soon as the output is loaded, the LM2852 begins normal
switching operation.
LAYOUT HINTS
These are several guidelines to follow while designing the PCB layout for an LM2852 application.
1. The input bulk capacitor, C
IN
, should be placed very close to the PVIN pin to keep the resistance as low as
possible between the capacitor and the pin. High current levels will be present in this connection.
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