デバイスごとのパッケージ図は、PDF版データシートをご参照ください。
TPS2373には、IEEE802.3atまたはIEEE802.3bt (ドラフト) (タイプ1-4)受電機器(PD)を実装するために必要な、すべての機能が含まれています。内部スイッチ抵抗が低いため、 TPS2373-4および TPS2373-3は、それぞれ最大90Wおよび60Wの大電力アプリケーションをサポートできます。100mのCAT5ケーブルを想定した場合、これはPD入力の71.3Wおよび51Wに相当します。
TPS2373は拡張機能付きで動作します。
DC-DC用の高度なスタートアップ機能により、単純で柔軟なソリューションを最小のシステム・コストで構築でき、IEEE802.3bt (ドラフト)のスタートアップ要件を満たすことができます。これにより、低電圧バイアス・コンデンサを大幅に小型化できます。また、DC-DCコンバータのソフトスタート期間を長くでき、低電圧のPWMコントローラを使用できるようになります。
自動MPS機能により、非常に消費電力の低いスタンバイ・モードが必要なアプリケーションにも使用可能です。 TPS2373は、PSE電力を維持するため必要な、パルス化された電流を自動的に生成します。外付けの抵抗を使用して、この機能を有効化し、MPSのパルス化された電流の振幅をプログラムできます。
型番 | パッケージ | 本体サイズ(公称) |
---|---|---|
TPS2373 | VQFN (20) | 5.00mm×5.00mm |
Changes from B Revision (March 2018) to C Revision
Changes from A Revision (October 2017) to B Revision
Changes from * Revision (June 2017) to A Revision
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
VDD | 1 | I | Connect to positive PoE input power rail. Bypass with 0.1 µF to VSS. |
DEN | 2 | I/O | Connect a 24.9 kΩ resistor from DEN to VDD to provide the PoE detection signature. Pull DEN to VSS to disable the pass MOSFET during powered operation. |
CLSA | 3 | O | Connect a resistor from CLSA to VSS to program the first classification current. |
VSS | 4, 5 | — | Connect to negative power rail derived from PoE source. |
CLSB | 6 | O | Connect a resistor from CLSB to VSS to program the second classification current. |
REF | 7 | O | Internal 1.5 V voltage reference. Connect a 49.9kΩ_1% resistor from REF to VSS. |
AMPS_CTL | 8 | O | Automatic MPS control. Connect a resistor with appropriate power rating (to support the MPS current) from AMPS_CTL to VSS to program the MPS current amplitude. Leave AMPS_CTL open to disable the automatic MPS function. |
MPS_DUTY | 9 | I | MPS duty cycle select input, referenced to VSS, internally driven by a precision current source with voltage limited to less than ~5.5V. A resistor connected to VSS determines if the MPS duty cycle selected is either 5.4% (open), 8.1% (~60.4 kΩ) or 12.5% (short). |
APD | 10 | I | Auxiliary power detect input. Raise 1.65 V above RTN to disable pass MOSFET, to force TPH active (low) and to force TPL and /BT inactive (open). If not used, connect APD to RTN. |
RTN | 11, 12 | — | Drain of PoE pass MOSFET. Return line from the load to the controller. |
PG | 13 | O | Power Good output. Open-drain, active-high output referenced to RTN. |
VC_OUT | 14 | O | VC output. Connect to the low voltage supply pin of the PWM controller. Bypass with a 1 µF to RTN in most applications. If the applications requires operations from a 12 V adapter, a higher capacitance value is needed. |
VC_IN | 15 | I | VC input. Connect to auxiliary bias voltage source, usually derived from an auxiliary winding of the power transformer of the converter. Bypass with a 0.1 µF to RTN. |
UVLO_SEL | 16 | I | UVLO select, referenced to RTN, internally pulled-up to 5.5 V internal rail. Leave open when the selected PWM has a falling UVLO above 7.25V. Pull UVLO_SEL low if it is between 4.25V and 7.25V. |
TPL | 17 | O | PSE allocated power outputs, binary coded. Open-drain, active-low outputs referenced to RTN. TPL becomes open and TPH pulls low if an auxiliary power adapter is detected via the APD input. |
TPH | 18 | O | |
BT | 19 | O | Indicates that a PSE applying an IEEE802.3bt (Type 3 or 4) mutual identification scheme has been identified. Open-drain, active-low output referenced to RTN. /BT becomes open if an auxiliary power adapter is detected. |
NC | 20 | — | No connect pin. Leave open. |
Pad | — | — | The exposed thermal pad must be connected to VSS. A large fill area is required to assist in heat dissipation. |