si3400 Silicon Laboratories, si3400 Datasheet - Page 8

• Manufacturer Part Number: si3400
• Description: Fully-integrated 802.3-compliant Pd Interface And Switching Regulator
• Manufacturer: Silicon Laboratories

Si3400/Si3401
Table 5. Electrical Characteristics (Continued)
Table 6. Total Power Dissipation
Table 7. Package Thermal Characteristics
8
Power Dissipation
Power Dissipation*
*Note: Silicon Laboratories recommends the on-chip diode bridges be bypassed when output power requirements are >10 W
Thermal resistance
(junction to ambient)
VDD accuracy @ 0.8 mA
Softstart charging current
Thermal Shutdown
Thermal Shutdown Hysteresis
Notes:
1. Transient surge defined in IEC60060 as a 1000 V impulse of either polarity applied to CT1–CT2 or SP1–SP2. The
2. The classification currents are guaranteed only when recommended RCLASS resistors are used, as specified in
3. IPORT includes full operating current of switching regulator controller.
4. The PD interface includes dual-level input current limit. At turn-on, before the HSO load capacitor is charged, the
5. See “AN296: Using the Si3400/01 PoE PD Controller in Isolated and Non-Isolated Designs” for more information.
6. Applies to non-isolated applications only (VOUT on schematic in Figure 1).
Description
(Si3401) or in thermally-constrained applications. For more information, see “AN313: Using the Si3400 and Si3401 in
High Power Applications”.
shape of the impulse shall have a 300 ns full rise time and a 50 µs half fall time with 201 Ω source impedance.
Table 11.
current limit is set at the inrush level. After the capacitor has been charged within ~1.25 V of VNEG, the operating
current limit is engaged. This higher current limit remains active until the UVLO lower limit has been tripped or until the
hotswap switch is sufficiently current-limited to cause a foldback of the HSO voltage.
Parameter
Parameter
VPORT = 50 V, V
VPORT = 50 V, V
bridges bypassed
Symbol
θ
JA
Condition
OUT
OUT
36 V < VPORT < 57 V
Junction temperature
= 5 V, 2 A
= 5 V, 2 A w/ diode
Preliminary Rev. 0.91
Still air; assumes a minimum of
nine thermal vias are connected
to a 2 in
the package “pad” node
(VNEG).
Description
2
Test Condition
heat spreader plane for
Min
—
—
Min
4.5
—
—
—
Typ
1.2
0.7
Typ
Typ
160
44
12
—
—
Max
—
—
Max
5.5
25
—
—
Units
°C/W
Units
W
W
Unit
µA
ºC
ºC
V